Be The One For All
by DarkAbyssBreak
Summary: Sento Kiryu, Izuku Midoriya. Both are heroes in their respective universes. Sento and his friends grow up in the world of My Hero Academia, leading to an opportunity at UA Academy. When these two heroes meet, the destinies of everyone in their world are set into motion. In the midst of this, the secretive Faust organization and the League of Villains begin to act.
1. Build:Origin

A young boy, about 7 years old, could be seen running out of the Touto Institute of Advanced Matter Physics. He was chasing after the red-colored armored stranger who had just murdered both of his parents.

"Hey! Get back here, you monster!"

The murderer then stopped running and just stood in place with his back turned, terrifyingly still. He then began to laugh and turned to face the child. The evildoer was holding what appeared to be a gun in his right hand and he had a snake-shaped visor on his face and a snake symbol on his chest plate.

"So, Kiryu Jr. thinks that he can stop me?"

"No, I know I can't. I just needed to get you out in the open where people could see you and call the heroes and police!"

"I see. It figures that you'd be able to hatch a plan like this, considering who your parents are, I'm sorry, _were_."

"I know why you killed my mom and dad, you're after the Pandora Box!"

"You keep on surprising me kiddo! Say, you wouldn't happen to know where it is?"

"You're the last person I would tell!"

The man sighs at the boy's declaration.

"Well, I can't just ignore that you've not only seen me, but you also saw me kill your folks."

The man then grabbed the young child, trapping him in a chokehold. He then placed one of his hands in front of the boy's face and smoke began coming out of it.

"I really don't want to kill a kid if I can avoid it, so I'll just take away your memories from when you ran out of the building to right now. However, I will leave you with this. My name is Blood Stalk. Remember the name of the man who killed your parents."

The kid passed out from whatever it was that Stalk did to him and Blood Stalk then left the scene. The civilian onlookers rushed to the boy's side, one man among them said:

"Somebody call the police!"

 **Two hours later**

Sento Kiryu woke up to the sound of ambulance sirens in the background. He was resting in a stretcher, and noticed that his parent's friend Soichi Isurugi and his daughter Misora were at his side, Soichi looking quite sad and Misora in tears.

"Soichi-san, what's going on?"

Mr. Isurugi looked at Sento with a patient look and said:

"Sento-kun, there is no easy way to say this, your parents were murdered."

All of a sudden, Sento's memories came flooding back to the surface, as the last thing he could recall was seeing the armored man stab both of his parents with some kind of blade after he had threatened them and they refused to comply with his demands. Soichi then told Sento something that would stay with him for years to come.

"What happened to Shinobu and Kyoka wasn't right, they were good people. Sento-kun, your parents told me that they stated in their will that if anything were to happen to them, that you were to be placed under my care as they named me your godfather." Sento, still fighting back tears, continued to listen to Mr. Isurugi. "Come live with us, Sento-kun!"

Misora chose then to speak her mind.

"Sento, I know that you just lost your family and that everything is very painful and confusing right now, but we'll help you! After all, you're my best friend!"

Misora then jumped at Sento and gave him the biggest hug that she could muster. Sento returned the hug with what strength he had left. He thought about it and said:

"Okay Soichi-san, I'll stay with you and Misora, you guys are the only family I have left."

Mr. Isurugi got up from the bench he was sitting on and placed his hand on Sento's shoulder.

"It's going to be okay." Seeing that things had calmed down somewhat, Soichi told Sento and Misora he was going to give a statement to the police as him having been friends with Sento's parents meant that he might have some information that could help the investigation. The fact that there were no heroes in the area when this had occurred placed the responsibility of finding the one responsible on the officers of the law.

"Misora, keep an eye on Sento-kun for me, will you?"

Misora wiped the tears off her face and smiled at her dad.

"Of course, daddy! I'll take good care of him, promise!" giving her dad a thumbs up.

"That's my girl."

As Mr. Isurugi was walking out of the ambulance, Sento remembered one last thing from that night. For whatever reason, he somehow knew the name of the monster who took his parents from him. He muttered under his breath, "Stalk".

Soichi heard what Sento said, even though he was a couple of feet away from the ambulance by now, and he smirked.

 _Name: Sento Kiryu_

 _Quirk: Nebula Gas - A mysterious quirk of unknown origin. Strange that he has a quirk, seeing as his parents were quirkless._

 _Name: Misora Isurugi_

 _Quirk: Quirkless._

 _Name: Blood Stalk_

 _Quirk:?_


	2. Deku:Origin

**Hi everybody, DarkAbyssBreak Here! This is my debut on this site and I thought, what better way to start things off than with a superhero fanfic?**

 **My Hero Academia is reaching new heights of success across the board, the anime is to die for and the manga keeps me coming back for more!**

 **I shed a tear watching the last episode of Kamen Rider Build, as that show shot up to be my favorite Kamen Rider season. After watching these two amazing shows, I just knew that I had to write something that unites the two, and this story is just that.**

 **Now, for some background knowledge. The world that everyone is living in is the My Hero Academia world. The Kamen Rider characters are a part of this world in this story, but seeing as there are some elements of the Build world that I liked, there will be stuff that I bring over. For example, I'll keep the Touto, Hokuto, and Seito regions as the My Hero world takes place in Japan.**

 **Sento and his friends will be one year older than class 1-A, so when it comes time for them to go to UA, they will be second years. Also, the Skywall didn't happen, but Japan is still sectioned for convenience.**

 **This fanfiction is going to have a bit of a slow beginning as I plan to flesh out both Sento and Izuku's origins as well as set up events for later on. Don't worry, Izuku's story will remain generally untouched as I'll be sure to keep things like Bakugo's treatment of him the same, and his encounter with All Might. However, he might bump into a certain genius before he takes his entrance exam.**

 **Now without further delay, I give you the second prologue chapter of Be The One For All, Deku:Origin!**

* * *

 **Deku:Origin**

"You're being a bully, Kacchan!"

Those words were spoken by one Izuku Midoriya, trying to keep Katsuki Bakugo and the two kids with him, one had stretchable fingers and the other sported devil-like wings, from hurting the defenseless kid that he was attempt to shield from his former friend.

Bakugo, amused by what he is seeing in front of him, said:

"Hey look guys, Deku is still playing at being a hero, even though he's just quirkless trash! Let's get him!"

Bakugo and his two cohorts then proceed to beat up Izuku using their quirks on him, leaving him battered and bruised on the ground. Izuku then thought:

 _Not all men are made equal. This lesson was literally beat into me at the age of four._

* * *

 **Ten Years Later**

 **(My Hero Academia OST – Hero A starts playing)**

Izuku is running, splashing a puddle while doing so. The walk signal reads stop and he is eagerly stepping in place, anxious to cross. He runs across an area with sakura trees, their petals being carried off by the wind.

He finally reaches his destination, Tatooin Station. A large monster is looking around for any sign of heroes. A crowd of civilians are gathered around, taking notice of the chaos that the criminal is causing. Izuku looks at the giant man and says:

"Oh wow! That Villain is big!"

 **(Music stops playing)**

 **Izuku is Narrating**

 _It all began in China, in some city. A child was born who gave off a glow of light. His dad was surprised to say the least._

 _Since then, around 80% of the world's population has shown signs that they possess a special power, or what we now refer to as a "quirk"._

 _We now live in a superhuman society where most people have quirks, and from that revelation, came trouble._

 _People began to use their powers for crime and evil acts. A quirked criminal could do a lot of harm if they decided to turn their abilities against the innocent._

 _Thus, there arose the need for strong, righteous protectors who could go beyond and stop evil from consuming our world. The unlikely idea that could only come from a comic book, could now be reality. Hero was made a profession for those of us who had the drive, power and heart to do what is right._

 _The number one hero, a hero among heroes, is none other than my personal idol, All Might._

 **Izuku stops Narrating**

* * *

Back to the present, the huge monster man smashes an telephone pole and just as it's about to fall on some civilians, a very strong looking man rushes in and grabs the debris. A businessman in the crowd points and shouts:

"Hey look there! It's Death Arms, The Punching Hero!"

Right then, a man whose appearance greatly resembles a firefighter used his quirk to create a stream made out of water to keep the crowd from getting too close. He is the rescue hero, Backdraft.

A figure covered in wood leaps onto to the scene, jumping a couple of buildings to get to where the criminal was. Kamui Woods arrived to put an end to this problem.

The giant man was not having any of this and told Kamui:

"Stay away from me!"

Meanwhile, Izuku made his way through the crowd to reach where the action was happening. He then asked:

"Who's fighting?"

He looked up and saw clearly, who was fighting the monster as Kamui was using his quirk to stretch his arm over to a nearby pole and pull himself out of the way of the huge man's fist.

"It's Kamui Woods! The young and talented rising hero!"

A fellow onlooker who was standing next to Izuku took notice of the young man geeking out and began talking to him.

"You're a fanboy, aren't you?"

Deku blushes at this, but doesn't correct the man.

Kamui proceeds to lecture the criminal.

"You are not only using your powers to cause destruction, you also wound up harming the woman whose purse you were trying to snatch. Truly, you are a bane to society and must be dealt with!"

Kamui then jumps onto the roof of a train waiting station and prepares to attack with one of his signature moves. "Pre-emptive Binding Lacquered Chain Prison!"

Just as the wooden limbs are about to encase the man, a female voice rings out, shouting:

"Canyon Cannon!"

An enormous woman is seen performing a drop kick, felling the evildoer and knocking him out cold.

The woman in question is wearing a cream and purple colored costume, highlighted with some orange, and is wearing a mask with horns coming out from it. She is the pro hero, Mt. Lady.

The police then took custody of the monster man, restraining him with capture equipment.

Izuku then added Mt. Lady to his hero notebook and muttered:

"Gigantification, huh? A great quirk, seems like she'll do well. She might run into some problems when she tries to get to places while she's huge."

The man from earlier asked Izuku:

"Hey, you want to be a hero, right? Maybe you'll do it, keep at it!"

Izuku thanks the man, saying:

"I'll do it! After all, it's my dream!"

* * *

The next day, Izuku goes to school and the negligent teacher mentions that it is time for applications to UA Academy to be submitted. Izuku's classmates all begin showing off their many quirks. Bakugo, hearing this, jumps up from his seat and stands very arrogantly on his table and declares:

"I'm the only person from this average high school with the potential to be accepted into UA! My quirk is powerful, I aced the mock test, and I've got too much skill! I almost feel sorry for the other applicants that will have to face me during the entrance exam, haha!"

The teacher chose then to mention:

"Oh yeah, weren't you also applying to UA, Midoriya?"

Bakugo then turns around and looks Izuku straight in the eyes, making the poor boy sink down into his seat.

The explosive blond haired boy used his quirk to create sparks in the palm of his right hand, using it to intimidate Izuku and told him:

"You're quirkless, below even those with lame-ass quirks that can't do anything, how dare you try to step in the same ring as me, you useless Deku!"

Elsewhere, a sludge creature is seen attempting to flee from any nearby heroes and police. All of the bystanders are shocked and screaming, trying to keep away from this dangerous individual.

Just then, a bony, skeleton looking man walks out of a convenience store holding a bag and assesses the situation. The civilians are talking about how they can't do anything as none of them are pro heroes. The skinny man then buffs up and a very muscular figure takes his place. The people notice who has just shown up and everyone gasps. All Might then proclaims:

"Fear not citizens! Why? Because I am here!"

* * *

"Hey you know Deku, if you still want to be a hero, there is a way to do it. Just pray that you'll get a quirk in your next life and take a swan dive off of the roof!"

Bakugo then storms off, leaving a depressed Izuku alone in the classroom.

Walking home, Izuku thinks to himself that Bakugo shouldn't have said that. If he wants to be a pro hero, he can't just casually tell someone to go kill themselves, even as a joke. "Stupid."

 **Flashback**

 _A young Izuku begs his mom to playing a video on the computer for him, as it's his favorite. Inko Midoriya then tells her son:_

" _Alright Izuku honey, you're probably responsible for most of the views on that video, you know? I can't stomach this sort of thing, so I'll leave you to your fun, okay?"_

 _The video begins playing as Inko leaves the room. Izuku is shaking back and forth in his chair while he is holding his All Might action figure._

 _The scene is utter chaos. There is a bus crashed into a car, and dozens of injured people. Out of nowhere, someone begins laughing very loudly. "Hahahahahaha!" All Might is seen with many people being carried on his back, and under his arms. He assures the people that everything is fine and says:_

" _I am here!"_

 _This inspires Izuku and he thinks to himself I've never seen anything or anyone that cool and amazing!. He then shouts: "When I get my quirk, I'm gonna be a hero just like him!", laughing much like his hero while his mom is watching him just before she leaves the room._

" _You should probably give it up."_

 _Those words were spoken by the quirk specialist that Inko took Izuku to see. The doctor went on to explain that due to Izuku having two pinky toe joints instead of one, like most quirked people do, that he would never develop a quirk._

 _Izuku is shown to be watching the same video of All Might rescuing people. He asks his mom, with a hopeful tone in his voice, "Mom… He saves everyone and still has the strength to smile in the face of danger…" He turns his chair to look at his mom "Can I… be a hero?"_

 _Inko quickly embraces Izuku and apologizes. "I'm sorry, Izuku!"_

 _Izuku thinks That's not it, mom. What I wanted you to say back then was…_

* * *

 **Flashback ends**

Izuku is standing in front of an underpass, still reeling from that painful memory. He clenches his left fist "I made up my mind back then, that I was going to be a hero no matter what anybody said!" As he steps forward, he accidently bumps into someone, causing the person to drop something. Izuku instantly apologizes "I'm so sorry! I wasn't looking where I was going!"

The young man who he bumped into looked to be about a year older than himself. He had smooth black hair, was sporting a large brown coat with a hoodie, and was wearing a blue shoe on his right foot and a red shoe on his left. Izuku then looked at what he dropped and saw what looked like bottles. One was red with a rabbit design and the other was blue with a tank on it.

The boy bent down to pick up the bottles and said "This is the worst." He then told Izuku "That's quite alright, accidents happen." Before walking off, he lifted his thumb and extended his index and middle fingers on his right hand, making a gesture near his head and said "See you."

After the stranger left, Izuku then said "Well, that was weird." He then entered the underpass like he meant to before. Just as he was halfway through, sludge-like liquid was oozing out of the manhole cover behind him. He heard some odd, and turned around to find the substance was forming itself into a Villain.

The evil slime then grabbed Izuku and said "Calm down kid, I'm just gonna take you over! I need someplace to hide and I've decided that you're it! You're seriously doing me a solid here, like a hero!"

Izuku was beginning to pass out and began to cry. He was going to die at the hands of this creature and he wouldn't live to achieve his dream of becoming a hero. _Somebody help! Please…_

The same manhole cover that the sludge monster slipped through flew off of the ground and who else should emerge but All Might!

"It's alright now, young man. I am here!"

The Villain takes a swipe at the hero, but All Might ducks and using incredible speed, zeroes in on the fiend and shouts:

 **TEXAS SMASH!**

The creature then bursts from receiving the full force of the wind pressure given off by one of All Might's signature smash attacks and the last thing that Izuku sees before passing out is his hero.

* * *

A few minutes later, All Might is attempting to wake the young man up, by tapping his face until he does. Izuku then opens his eyes and sees All Might right in front of him, who says "Thank God!" Izuku immediately starts freaking out and stands up.

All Might, noticing that the young man in front of him is still a little frazzled, explains "Sorry I involved you in my fight against evil, young man! I was probably a bit overzealous as this is my first day off spent somewhere new. Hahahahaha!" All Might then pulls out two soda bottles, containing the now trapped sludge Villain and says "I caught him!"

Meanwhile, Izuku is still freaking out that All Might is actually in front of him. _It's really him, the number 1 hero!_ All Might is shown to be giving a massive grin. _It's totally different, now that I'm meeting him in person!_ Izuku then remembers something "All Might, would you please sign my…" only to see that All Might has already autographed Izuku's hero notebook. Izuku then bows to All Might and says "Thank you so much!"

All Might tells Izuku that it's no problem and that he needs to give the Villain over to the police.

Izuku asks "Wait, you're going already?"

The hero tells the boy "Heroes battle not only Villains, but time as well!"

As All Might bends down and uses his power to launch himself into the air, He finds that he is plus one passenger as Izuku grabbed onto the hero before he made the leap.

All Might then tells the boy "Hey, I understand hero worship, but this is going a bit too far, don't you think?" Izuku replys "If I let go of you now, I'll fall and die! Also, I've got some things that I need to ask you!" Realizing what the boy said is true, All Might then looked around for an empty rooftop that he could safely land on. As he was doing this, some blood began to leak from his mouth before he wiped it away and said "Shit."

 **(Heroes by Brian the Sun starts playing)**

After he landed the both of them atop of a safe building, All Might was ready to walk off, when Izuku, remembering his mother's apology and Bakugo's insults asked, "I don't have a quirk, but can I still be a hero? Can someone with no power even dream of being someone as amazing as you?"

 _I wouldn't know it then, but that once in a lifetime encounter with All Might would shape my destiny in ways that I couldn't even begin to imagine._

* * *

 **A/N: And there is Deku's prologue. Now, the next couple of chapters will serve to develop Sento and his friends some more, so I'll do this then. I'm going to run a blind poll to determine which of Build's fellow riders will the first one that he meets for the first time next chapter. The choices will be:**

 **Banjo Ryuga (Kamen Rider Cross-Z)**

 **Kazumi Sawatari (Kamen Rider Grease)**

 **Gentoku Himuro (Kamen Rider Rogue)**

 **The poll will end at 12:00 AM Midnight on Monday October 8, 2018, so vote soon!**

 **Having said that, the next update will be sometime after I collect the poll results and a winner is chosen. So expect the next chapter after a few days. DarkAbyssBreak out!**


	3. A Genius meets a Dragon

**Well, the results for the poll are in! The winner, with 6 votes, is our resident muscle head, Ryuga Banjo! Sento will be meeting him in this chapter. Also, Sento is still recovering from his parent's murder and he's adjusting to living with Soichi and Misora.**

 **For those of you who've watched Kamen Rider Build, you'll notice that Sento Kiryu and Katsuragi Takumi aren't the same person. That's because I plan to have the "Devil's scientist" show up later on.**

 **I always felt really bad for Ryuga in the show, as he got a pretty raw deal with everything that happened to him, save for meeting Sento and everyone else. So, I have opted to have him be with his girl, Kasumi Ogura. In addition, since Katsuragi won't show up til later, Ryuga will not be implicated for his murder as that won't happen.**

 **Anyhow, let's get right to the next chapter! Here it is!**

* * *

 **A Genius meets a Dragon**

 **Four years after Shinobu and Kyoka Kiryu were murdered**

11-year-old Sento Kiryu was sitting down at a table in the nascita café. He was sipping a cup of coffee, while reading the head article of the newspaper he was holding. It read "One Year since Sento Kiryu inherited The Touto Institute of Advanced Matter Physics from his parents, ushers in a new era of science!"

Sento, glancing at the front page, thinks: _Mom, Dad, I hope that I've truly been living up to the legacy that you both left behind._

It had been 4 years since he had gone to live with Mr. Isurugi, or as he is known as by his customers, Owner, and his best friend Misora. They had taken a sad, lonely, orphaned boy and shown him nothing but love and kindness. He truly valued them for that and they held a special place in his heart.

He thought back to last year when Owner had helped him take his rightful place as the Head of Touto Institute of Advanced Matter Physics and learned what his parents were working on.

 **One year ago**

 _The conference room of the Institute of Advanced Matter Physics was ablaze with arguments. Many of the board advisors were shouting out what they believed to be the best direction for the Institute going forward._

" _We should keep to what we've been doing all of these years!"_

" _Things need to change around here!"_

" _We have to start reaching out to other companies, so we can maintain our resources and profit!"_

" _What about the science and improving people's lives?"_

 _Just then, Soichi Isurugi, who was present as Sento Kiryu's legal guardian and counsel spoke up. "Now, now, esteemed members of the board, you are all forgetting about the young man who is in charge here!" The advisors then turn to look at Sento Kiryu, sitting at the head of the table, with a contemplative look on his face. He decided to voice his opinion on the matter:_

" _My mother and father were brilliant."_

 _This statement silenced all of the board members as they remembered the wonderful former heads of the Institute. Sento continued:_

" _In their will, they both stated that when I was to reach 10 years of age, that I would be instated as the head of this Institute. I have heard all of your claims and have come up with a solution that should satisfy everyone."_

 _All of the members then focused on Sento, curious as to what he had come up with. He said:_

" _My parents were murdered because they were in possession of the Pandora Box. That is likely what the murderer was after. Even when I saw him threaten their lives, they protected not only the box, but also my life. My plan is for us to continue researching the secrets of the Pandora Box, and using what we learn from it to benefit humanity!"_

 _One bold advisor chose then to question the boy:_

" _How do we know that this will lead to any credible results?"_

 _Sento replied:_

" _We are all aware that the Pandora Box was discovered on Mars by my godfather and former astronaut, Mr. Isurugi here." Soichi gave a small grin, and took a bow._

" _The research notes that my parents compiled lead to the conclusion that the Pandora Box is an object of great power belonging to an extraterrestrial civilization. The wealth of knowledge that we could obtain, make investing the effort to this project priceless!"_

 _Sento then stands up from his seat and bows at a 90-degree angle to the board, pleading "I implore all of you, who have aided my parents for countless years! Please lend me your support!"_

 _Sento looked up to see the entire board standing and clapping for him, every one of them stating they will support him with all that they can._

* * *

 _After the meeting was over, Sento and Mr. Isurugi made their way over to Mr. and Mrs. Kiryu's former lab. Once they were alone, Soichi decided to reveal something to Sento and said:_

" _Sento-kun, there is something that you need to know. Your parents left behind a video record on their computer with information for you."_

 _Soichi motioned for Sento to access his parent's computer. Sento knew what the password was to log in, he typed BUILD and the screen opened up. Owner pointed out: "Click on the folder named Project Build, and then click on the file named Rider System."_

 _Sento did just that, and a video started playing. His father was facing the camera, wearing his lab coat with his arms crossed behind his back. He started to explain: "Hi there, son. If you are watching this, it means that your mother and I are dead." Sento looked down when he heard that, still coming to terms with his deceased parents. "Do you remember the time that your mother and I had you enter a chamber and we flooded it with gas?"_

 _Sento remembers the experiment that his father is referring to._

" _Well, we made a revolutionary discovery regarding the Pandora Box! It turns out that exposure to the gas that can be manufactured from the object, can grant a quirkless individual a quirk! Something that before now, was completely unheard of!"_

 _This information surprised Sento as he knew that the Pandora Box was important, but this was simply ground-breaking!_

 _His father further added: "We have dubbed the quirk "Nebula Gas", given the origin of the Box. Under safe conditions and extensive testing, your mother and I chose you to be the first test subject to receive this quirk."_

" _We have always regretted the fact that all we've ever given you as you were growing up was knowledge and tools. I can remember once when you were 5, that you once told me that you wanted to be a hero who can protect the idea of love and peace. Your mother, when she heard what you said, approached me about making your dreams a reality."_

 _Kyoka Kiryu came onto the screen as she was tucking in a 5-year-old Sento to bed. She sat down with her husband and asked: "Shinobu dear, can Sento really become a hero like he wants to? I don't want to end his dream!" Shinobu tells Kyoka what he discovered the other day: "Honey, while I was researching the Pandora Box, I found out something unique about its properties!"_

 _Dr. Kiryu told his wife about how the Pandora Box could potentially grant a quirk to someone who was quirkless. Kyoka excitedly cheered:_

" _This is wonderful news, not only could this help those who want to become heroes even though they're quirkless, but we could help our dear Sento reach his goal!"_

 _Back to Dr. Kiryu, "From then on, your mother and I devoted most of our time and brainpower to using the Pandora Box to give you a quirk. Fast-forward a year, we finally created a chamber that could safely contain the Nebula Gas and we put you in the chamber. After a full day of exposure, we conducted a toe x-ray on you, and lo and behold, you now had a quirk. We had succeeded!" You didn't remember any of what had happened to you that day, as a side effect of the Nebula Gas experiment is zero recollection of the procedure."_

" _Anyhow, your quirk is named "Nebula Gas" and from what we could tell, this quirk allows its user to utilize the power of the essences in living and non-living things. However, it appears the user cannot do this without additional assistance. To that end, we created what we have dubbed the Rider System. Your profile in the Rider System was named Project: Build, as we remembered how much you loved to build things with us, whether they were towers constructed from blocks, to complex machinery and gadgets."_

" _The final step of the Rider System, was the creation of a device called the Build Driver." Shinobu held up in his hand, what looked like a belt with a buckle fitted with two empty slots and a crank handle hanging off of the left side. "We have determined that "Nebula Gas" is a transformation-type quirk that relies on bottled essences to transform the user into an armored hero, I have named a "Kamen Rider" or masked rider."_

" _I had your mother perform the Nebula Gas procedure on myself, so that I could visibly test how transforming using the Build Driver works. We made 60 fullbottles using the Pandora Box, 30 containing organic essences and 30 with inorganic ones. One can place any organic bottle with an inorganic one to transform. However, should you pair two bottles that are perfectly compatible, that will result in a best match. For example, the rabbit fullbottle and the tank one are a best match. One must achieve a Hazard Level of 3 or more to use the driver. A Hazard Level is a measure of how potent the Nebula Gas energy is within someone with the quirk."_

 _Dr. Kiryu is seen placing the Build Driver on his waist. He turn shakes the rabbit fullbottle in his right hand and the tank bottle with his left. Physics equations, formulas and variables begin to come out of nowhere. Dr. Kiryu then places the bottles in the slots and the Build Driver announces:_

 **RABBIT!**

 **TANK!**

 **BEST MATCH!**

 _Dr. Kiryu informs the viewer: "Lastly, turn the lever on the side of the driver and transform."_

 _He then turns the levers and the driver asks:_ **ARE YOU READY?**

 _Dr Kiryu says: "Henshin!"_

 _The Build Driver produces two halfbodies, one red and one blue, both halves snapping into place. The result is an armored figure with a blue tank for the right visor and a red rabbit for the left visor, sporting a red and blue body. The driver then says:_

 **FULLMETAL MOONSAULT!**

 **RABBIT! TANK!**

 **YEAH!**

 _Shinobu disengages the transformation and says: "Sento, this Build Driver is yours. It is my hope as your father that you use it to help others and make the world a better place." Kyoka shows up on screen, smiling next to her husband "Sento, we are so proud of you, son. We believe in you and we love you!"_

 _The video ended at that point. Sento turned over to Soichi and the man was holding the Build Driver. "Your parents wanted me to hold onto this for you until I felt you were ready. After what I saw in these conference room earlier, I believe that you are now ready." Owner then handed the driver over to Sento._

" _Thank you very much, Owner!" Sento was thankful that Mr. Isurugi was always looking out for him. "I'll make you and my parents proud!"_

* * *

 **Back to the present**

Mr. Isurugi and Misora came up to Sento, who had just finished remembering all that had happened to him that day. Soichi spoke up:

"Hey Sento-kun, Misora and I were going to go watch a junior league boxing match! Apparently, one of the boxers is a natural fighter and his name is getting out there. He's become quite famous and we thought that you might want to spend the day with us!"

Sento asks: "What's this amazing boxer's name?"

Misora tells him: "His name is…"

"Ryuga Banjo! Your last match is in 10 minutes!"

"Got it!"

Sitting on a bench in the locker room, was 11-year-old Ryuga Banjo. The undefeated, junior league boxing champion for 2 years. He was resting up while waiting for his last match of the day. He needed to make sure that he won this last match to maintain his undefeated streak.

"Ryuga!"

A very beautiful brunette girl wearing a pink jacket, ran over to Banjo and gave him a peck on the cheek. Ryuga, surprised by the girl asks:

"Kasumi! What are you doing here?"

Kasumi then pouts and crosses her arms, telling Banjo:

"What, can't your girlfriend come over and cheer you on?"

Banjo smiles and tells her:

"No, you're allowed to. After all, you're my favorite fan!"

Sento, Misora and Mr. Isurugi are resting comfortably in three front row seats. Sento munching on some pocky, Misora nibbling on popcorn, and Soichi enjoying a hot dog, with ketchup and mustard. Curious, Sento asks Owner:

"How did you get these seats?"

Soichi replied:

"I know some people in the boxing circuit and they hooked me up, once I told them that I wanted to see this match."

The announcer then began to start the final match:

"Ladies and Gentlemen! Here is the final match of the day! In the right corner, we have the challenger, the rookie with a 8:2 win ratio, Genji Mako!"

The crowd cheered for the young man, who looked to be quite strong and had well-defined muscles.

"On the left side, the reigning champion! Sporting a 12:12 win ratio and the growing talent of Touto's junior boxing scene, Ryuga Banjo!"

The audience erupted into cheers as Banjo stepped into the ring and smirked at his opponent.

Misora asked Sento: "Hey Sento, who do you think will win the match?"

Sento observed the two boxers and told her: "Banjo should be the victor if he doesn't underestimate his opponent."

The referee raised both of his hands and blew his whistle, starting the match.

Banjo started to whale on Genji, trying to end the match with a TKO, but unlike his earlier matches, Genji was taking his punches like a pro.

Eventually, the match is tied at 2 wins a piece, and this fifth round is the decider. Sento, for whatever reason, decides to make his way down to the left side of the boxing ring.

Misora sees this and shouts:

"Sento! Where are you going?"

He yells back: "I'm going to give that muscle head a tip!"

Banjo is looking very haggard, fatigue from the earlier matches setting in now, and to make matters worse, Genji barely looks like he took any damage. _Oh crap, I might actually lose this match! No! I can't lose the finals of the Touto junior championship. I'll lose my sponsors and I won't be able to take Kasumi out on a fancy dinner date or get her that necklace that she's had her eye on!" She's the reason that I've made it this far, I've gotta do this for her!"_

Banjo looks out in the crowd and spots Kasumi looking at him with a worried expression, holding her hands together.

He then takes notice of a boy about his age, with smooth black hair, wearing a brown coat trying to catch his attention.

"Hey Banjo! Come here a sec!"

Banjo is confused by the stranger, but his sixth sense is telling him to hear the guy out.

"You need to perform a reverse feint with your left to his jaw!"

Banjo then stares at Sento and ask:

"How do you know that will work?"

Sento answers:

"I'm sure that after going 4 rounds with the guy, you've noticed that he tends to cover his jaws with his gloved fists when he's not attacking. All you have to do, is get past his defense when that happens and go for the kill!"

Banjo hesitates:

"What do you know about boxing?"

Sento honestly responds:

"Not much, but I do about a million things about Physics!"

The referee begins the final round of the match.

Genji tells Banjo in a confident tone: "Looks like your undefeated streak ends here, Banjo!"

Banjo throws a punch with his right and just like Sento said would happen, Genji pulled his fists to his face to protect his face.

Banjo thinks _Alright, here goes everything!_

Banjo uses his right fist to swipe at Genji's guard and he manages to create an opening. Taking full advantage of this, Banjo then uses his left to sock Genji square in the jaw, knocking the young boxer down to the ground. As the referee begins the count, he notices Genji is out cold and says:

"Genji is knocked out, the winner by KO is Ryuga Banjo!

Cheers and shouts explode from the crowd and Banjo can hardly believe it. He actually won! He sees Kasumi making her way towards him and hugs him fiercely, sobbing into his chest. She mutters: "Congratulations, Ryuga!"

He hugs her back and remembers something. He had to thank the guy who gave him that advice that helped him beat Genji. He scanned the crowd of people, but he couldn't find the guy.

* * *

Sento, Misora and Soichi are ready to leave the building to go home. Misora asks Sento:

"Sento, why did you help out that Banjo guy?"

He states:

"I felt like I couldn't just let someone with all of that potential lose like that."

Misora smiles at him and says:

"Aww! Sento is just a big old softie, isn't he?"

Soichi joins the conversation:

"You're absolutely right there, Misora!"

Sento just shrugs.

As the group is about to leave, a voice stops them.

"Hey, wait a sec!"

The 3 turn around to see Ryuga Banjo and his girlfriend Kasumi running over to them.

Sento, addresses the boxer:

"It's you, Mr. champion. What's the matter?"

Banjo tells him:

"Dude, I seriously owe you one for that killer advice that you gave me!"

Kasumi then proceeds to thank Sento as well:

"Ryuga told me what you said to him, and I appreciate it very much!"

Sento answers:

"No problem, I was happy to be of help!"

Banjo asks:

"So dude, is there any way that I could repay you for helping me?"

Mr. Isurugi decides to speak up:

"Well, you and your girlfriend could come over to our humble little café, nascita, for some snacks and coffee. What do you say?"

Banjo looks to Kasumi, who nods in approval and he says:

"Sure thing, that sounds like fun! Oh, before I forget, what are your names?"

"I'm Sento Kiryu."

"Misora Isurugi!"

"Soichi Isurugi."

"Well, you guys can call me Banjo and this is Kasumi!"

 _Name: Sento Kiryu_

 _Quirk: Nebula Gas_

 _Name: Ryuga Banjo_

 _Quirk: Quirkless_

 _Name: Misora Isurugi_

 _Quirk: Quirkless_

 _Name: Kasumi Ogura_

 _Quirk: Quirkless_

* * *

 **A/N: Sento and Banjo have finally crossed paths! More of Sento's past is being revealed. Next chapter will see Banjo and Kasumi visit the nascita café and get to know Sento, Misora and Soichi better.**

 **Maybe a certain Rogue might rear his head and make an appearance!**

 **Anyhow, due to College and life in general, the next chapter could be out anywhere from 3-5 days. So, don't expect a quick update.**

 **Thanks for the support, DarkAbyssBreak out!**


	4. A Rogue Encounter with Faust

**Hello there viewers, I'm back! Found myself with a lot of free time, so I got to writing. Now, this chapter will focus on the interactions between the Build characters. Namely, Sento and Ryuga, as well as Misora and Kasumi.**

 **Also, this is the point in Sento's story where things really start to pick up and events begin to unfold. We finally see Sento debut as Kamen Rider Build! This chapter will have a bit of everything, friendship, love, fear, hope, determination, politics, and mystery. It will also show how the Touto region operates in the My Hero world and the implications down the line. Other important details and people will either appear or be mentioned.**

 **Gentoku Himuro, or Rogue as most of you know, will appear alongside his father Taizan Himuro. They both will have something they want to discuss with Sento, given his position as the Head of the Touto Institute of Advanced Matter Physics.**

 **Faust will make their move and test out the waters to see how their emergence will impact society. Oh, almost forgot! I do not own Kamen Rider Build or My Hero Academia. I also do not own any of the soundtracks mentioned.**

 **Now, let's continue the story!**

* * *

 **A Rogue Encounter with Faust**

 **Nascita Café**

Sento, Misora, Soichi, and their two new companions, Ryuga and Kasumi arrived at the café as promised.

Kasumi takes a look at the building's appearance and remarks:" Wow! What a quaint little place, I can't believe that a gem like this is hidden away in an alleyway!"

Misora says:" We get plenty of business during all times of the day. It helps that dad not only pays for advertising via radio, but that whenever we get a new customer, they enjoy the food, drinks and atmosphere so much, that they tell all of their friends and become regulars."

Mr. Isurugi just then got a call on his cell phone, indicated by the vibrating in his pants pocket and said:" I'm sorry, everyone. I have to take this call, it could be important. Sento, Misora! Why don't the two of you take Banjo and Kasumi into the café and take their orders? My treat, of course! We had such a great time watching your match, so consider this as thanks!"

Soichi then took a walk, to see what the person calling him wanted.

Sento, then said: "Well, you all heard Owner. Come right in!"

Sento and Misora led Ryuga and Kasumi into the café. The interior of the place looked very comfortable and homey. The café table was green with a brown surface top, with 6 stools placed in front. There were square tables positioned all around the space, and there were shelves with different labeled coffee blends on them. A few ceiling lamps adorned the café and the menu was a blackboard with the specials written in colored chalks.

Ryuga asked them: "What do you guys do for work here?"

Misora answered: "Well, I'm the waitress around here and Sento is part-time staff."

Ryuga then remembered that he had something he wanted to ask Sento: "Hey Sento, how did you know what my opponent from today's match was going to do?"

Sento responds: "Oh, well that's because I'm a physicist!"

To that, Banjo says: "Wait, you're 11 just like us, right? No way you're really a physicist this young!"

Misora tells Banjo: "He's not lying."

Kasumi suddenly realizes: "You're Sento Kiryu, aren't you! The genius boy who graduated from Touto University last year after a single semester and became the head of the Touto Institute of Advanced Matter Physics!"

Banjo immediately apologizes: "Dude, I take back what I said. You're a genius then, that's how you could tell how I could beat Genji."

Sento says: "You're good, Banjo. I'm not offended that you didn't assume that I was a genius. After all, appearances aren't everything. Now, Banjo and Kasumi, may we take your orders?"

Kasumi tells him after going over the menu: "I'll have a piece of strawberry shortcake and a caramel mocha cappuccino, please!"

As Banjo is about to order, Kasumi does it for him: "Ryuga will have the chicken bacon club sandwich and a black coffee with one sugar!"

Sento asks Banjo: "Are you good with what your girlfriend ordered?"

Banjo replies: "Yeah, Kasumi knows what I like, like how I take my coffee black and that I love bacon! She takes very good care of me!"

Banjo gives Kasumi a side hug, making her blush due to the closeness.

Sento then says: "Okay you two, your orders will be ready in 10 minutes. Misora will seat you both and keep you company, while I prepare your orders.

* * *

Sento goes into the kitchen in the back, and Misora gestures Banjo and Kasumi over to the counter to sit on the stools.

Kasumi asks Misora: "So, what's the story with you and Sento?"

Misora smiles and tells them: "We're dating. We've been together for about a year now."

Banjo's eyes open wide, turning to looking right at Misora and he asks: "Wait a minute, he's not your brother or something?"

A sad look displays itself on Misora's face and she explains: "I've known Sento since we were babies apparently, from what my dad has told me and shown me in baby pictures. About 4 years ago, Sento's parents, who were the former heads of the Institute, were murdered. The person who did it was likely looking for something and threatened Mr. and Mrs. Kiryu to get it. At least that was the story the police gave us. Poor Sento saw that monster kill his parents right in front of him."

Banjo looks very shocked, while Kasumi puts her hand over her mouth and says: "How horrible."

Banjo adds: "Looking at the guy now," leaning over to see Sento cooking some bacon in a skillet, resting some boneless fried chicken on a wire rack and whistling while he cooks "you wouldn't think that kind of stuff happened to him."

Misora continues: "After that happened, Sento was tended to by paramedics in an ambulance. They called my dad because he was Sento's emergency contact. My dad and Sento's parents were really close friends, my mom was too, before she died. Dad told me what happened to Sento and I begged him to take me with him, I had to help Sento. Mr. and Mrs. Kiryu wrote in their will that my dad would be made Sento's legal guardian should they die, as he was already his godfather. When we went to see him, we comforted him and invited him to come live with us."

"So, to answer your question Banjo, no he is not my brother, but he'll officially be family once I marry him."

Banjo and Kasumi are gob smacked by what Misora said so casually.

Banjo follows up by asking: "Is your dad okay with you and Sento dating?"

Misora grins and says: "Are you kidding me? He was over the moon when we told him. Dad is usually very protective of me regarding boys but seeing as we've known Sento forever and dad already thinks of Sento as a son, he gave us his blessing and told us that he was kinda hoping that I'd end up with Sento."

Kasumi tells Misora: "Well, good for the both of you! I think that you guys make a cute couple!"

Misora thanks Kasumi: "I'm glad you think so!"

* * *

Just then, Sento steps out with Banjo's sandwich and Kasumi's cake, placing the plates in front of them: "Here you are, treasured customers! One chicken bacon club and one strawberry shortcake. Your coffee will be out in just another minute!"

Kasumi marvels at the shortcake and says: "Oh wow! This looks amazing! Thank you, Sento!"

Banjo is equally impressed with his sandwich and thanks the genius as well: "Yeah, this is one of the best-looking sandwiches that I've seen in a while!"

Sento gives a curt bow and replies: "Just a humble genius working his culinary science!"

Misora makes her way over to where Sento is and lightly slaps the back of his head, saying: "It wouldn't kill you to be a bit humbler, you know. Humble people don't go around saying that they are!"

Sento cheekily responds: "Yes, dear."

Misora blushes a light pink, then hits Sento with a nearby cloth and tells him: "Why don't you go check on our customer's coffee, you goof!"

Sento does just that.

Kasumi observes: "Forget you guys getting married someday, you both already behave like an old married couple!"

Misora decides to then ask Kasumi: "So, how did you and Banjo meet and get together?"

Kasumi tells her: "We went to the same elementary school and we just clicked. Sure, I was friends with all of the other girls, but Ryuga just had something to him that drew me to him."

Banjo adds: "It was the same for me too, Kasumi!"

At that, Kasumi gives Banjo the nicest smile she has and says: "Thank you, Ryuga!"

She continues: "It was one day when we were 9 and I was walking home from school. Some punk boy who had transferred in from Shiketsu elementary in the Seito region, came up to me and demanded that I go on a date with him. I rejected him immediately, and he didn't take that too well. He grabbed my arm and tried to pull me away, when I heard someone shout at him."

Banjo speaks up: "It was me, right!"

Kasumi giggles at the interruption and says: "Yes Ryuga, it was you."

Kasumi goes back to where she left off: "Ryuga showed up and saw the guy harassing me. He socked him really good in the face. The creep had a quirk that could slightly dull a person's reflexes, but sadly for him, it has little effect on somebody who is as physically fit as Ryuga. Ryuga chased him off and we've been in love ever since!"

Misora comments: "Aw! That's so sweet!"

Sento returns with the coffees and Banjo and Kasumi finish their food and begin drinking their coffees. Sento asks: "I heard everything from the kitchen, is being a hero what you're all about, Banjo?

Banjo suddenly looks down and gets a bit troubled. Kasumi, sensing what is going on through Banjo's mind says: "Ryuga had wanted to be a hero for so long, but he never manifested a quirk by age 4, so he was deemed quirkless."

Banjo then speaks up and says: "I always wanted to do something that could make a difference in people's lives. It's really tough for some folks out there and I thought that if I could become a hero, more people could be helped than if I weren't. When I found out I was quirkless, I turned to boxing as a way to cope with the news that I couldn't be a hero. Kasumi wanted me to end on this season, as were I to go into the pro circuit, there is a real chance that I could get seriously injured and neither of us want that to happen to us this soon."

Sento remarks: "You just keep on surprising me. Given how you seem to act, I initially believed that you'd be the type to make Kasumi happy but still try to be a hero."

Banjo says: "Well, I'm really lost right now, I'm done with boxing and I can't be a hero, so I don't know where to go next."

Sento exclaims: "You know, I have something of an offer that could solve most of your problems!"

Just as Sento was about to go into more detail, Mr. Isurugi walked through the front door and interrupted: "Sento, I just got a call from Touto's Prime Minister! He says that he wants to have a word with us, all of us present, including Banjo and Kasumi for some reason!" Soichi said in a hurry.

* * *

 **Touto Ministry of Defense**

About one hour later, Sento and company found themselves in front of the Ministry of Defense building. The two guardians who are standing to the sides of the glass doors, open them for Prime Minister Taizan Himuro and his aide and son, Gentoku Himuro.

Taizan greets the party in a diplomatic manner: "My apologizes for summoning you all here, I found myself needing to talk with some of you, specifically young Sento and Ryuga here.

Banjo, who is confused by the suddenness of everything asks: "Why would you need to talk to me of all people, Mr. Prime Minister?"

Gentoku corrects Banjo saying: "That's Minister Himuro to you, you simpleton!"

Taizan then scolds Gentoku: "Gentoku! That is not how one in a position such as yours ought to address one of his fellow citizens, moreover, an outstanding example like Mr. Banjo right here. Apologize to him!"

Gentoku reluctantly did so: "Please forgive my earlier insult."

Kasumi had a piercing gaze pointed at Gentoku, only calming down once Banjo said: "That's alright, I heard worse things from worse people."

Kasumi was so proud of Banjo for keeping calm and demonstrating self-control as she was about to defend him very vocally had he not done that.

The Prime Minister resumed: "Ryuga Banjo, you were called here because for two consecutive seasons now, you have remained undefeated in Touto's junior boxing league. There were many people, some of whom are in power, who held interest in seeing you move up into the Pro circuit. I merely wanted to know your reason for ending your success when you have the opportunity to go further."

Banjo answers: "That's easy, I'm bowing out for Kasumi. She is very concerned that I could sustain an injury in the Pro league that I might not be able to bounce back from. Also, boxing was more of an outlet for me than anything else, I was never living for it."

Taizan simply says: "Well, that's a shame. But, I suppose that everyone is entitled to choose their path in life and I do hope that you find yours."

Banjo responds: "Thank you for being so understanding, Minister Himuro!"

Gentoku is mildly impressed by Banjo's politeness, as he referred to his father by his proper title.

Taizan then looks over to Sento Kiryu and discusses what the purpose of them being there was: "Now Sento-kun, I've called you over because I have something I wish to ask of you."

Sento replies: "So long as you don't ask me for anything absurd, I'll be willing to hear you out."

Taizan puts all of his cards out on the table and asks: "Would you be willing to allow us to safeguard the Pandora Box?"

Misora and Soichi both appear worried and shocked that the Prime Minister would make such a request, especially to Sento. Banjo then asks: "What is this Pandora Box?"

Kasumi then informs him: "Ryuga, don't you remember? That was an astronaut a while back who went to Mars and returned with a black box that looked like it was alien in origin." Kasumi then looks at Mr. Isurugi and says: "Isn't that right, Mr. former astronaut?" Soichi looks sheepish and says: "Now, Kasumi-chan, that was a long time ago."

Sento, after a few seconds of contemplation, asks Taizan: "Minister Himuro, for what reason do you feel that issuing protection for the Pandora Box is necessary?"

Taizan Himuro looks hesitant to answer the young genius, when Gentoku interjects: "Look here, Kiryu. We know for a fact that the man who killed both of your parents is still at large. He will most likely make another attempt at getting the box, possibly at the cost of your life, and the lives of your family and your workers at the Institute."

Sento counters: "That sounds like a threat, Gentoku!"

Taizan immediately tries to defuse the tension: "My son didn't mean it like that, Sento-kun. He merely believes that the murderer, still being out there, will return and another incident much like your parents' unfortunate demise will occur. It is my responsibility as Prime Minister to ensure that something like that does not happen again."

Sento rebukes: "It shouldn't have happened in the first place!"

Misora goes to Sento and holds his hand to calm him down, while Soichi places his hand on Sento's shoulder.

Gentoku, furious with Sento blasts: "How dare you! Do you realize what my father goes through in order to keep Touto's fragile peace as stable as it is? He has to negotiate with leaders from the neighboring nations Hokuto and Seito, in order to keep the 3 powers balanced so that neither of the 2 get the idea that we are weak as a country and attack us! Their quirks wouldn't even be an issue. The Pandora Box could change all of that! With the limitless potential that item holds…"

Taizan moves to squash that line of thought: "Gentoku, son, we've discussed this before, using the Pandora Box in such a manner will give the other nations the justification to wage war and we have to prioritize the happiness and wellbeing of Touto's people!"

Gentoku then looks at Sento as the genius is trembling at having been made to remember the worst day of his life.

Gentoku sincerely says: "I'm truly sorry, Sento Kiryu."

Sento composes himself and says: "Look, I'm sure that you have only the best of intentions, Minister Himuro. You are a kind and reasonable man. As your son has pointed out, were I speaking to the Prime Ministers of either Hokuto or Seito, they probably would have just taken the Box without asking for my permission. Seeing as you have made the effort to politely request to protect the box, I'll accept. However, I have two conditions!"

Taizan, seeing that Sento was now allowing for them to help safeguard the box, said: "Name your conditions, Sento-kun."

Sento lays out his two conditions: "One: The Pandora Box will be stay in 3 locations, The Institute for research, the Ministry for safeguarding, and our café for personal use. Two: If you learn anything about the Pandora Box while it is in your possession, you will swear to act in accordance to Japan's code of ethics and not use the findings in such a way that threatens Japan or quite possibly the world. Accept these two conditions, and I will grant permission to protect the Pandora Box."

Taizan and Gentoku have a guardian bring out some parchment and a pen. They draft the agreement and include Sento's conditions. Mr. Isurugi then reads over the agreement and tells Sento: "Okay Sento, everything seems to be in order!"

Misora smiles at him and nods.

Sento picks up the pen and puts down his signature.

He tells the father and son duo: "You both know about how my mom and dad devoted themselves to uncovering the secrets of the Pandora Box in an effort to help society, right? Banjo, this is relevant to you too."

Banjo wonders what Sento is talking about.

Sento explains: "They finally discovered what the Pandora Box can be used for and left me the data they received from their research."

The eyes of everyone present except for Mr. Isurugi and Misora, widened considerably.

Taizan asked cautiously: "Sento-kun, you and your family have managed to discover some of the secrets of the Pandora Box?"

Sento nods and replies: "Yes, we have."

Before Sento could elaborate further, five bizarre looking creatures appeared out of nowhere and began to attack the ministry.

* * *

 **Ten minutes later**

Sento, Banjo and Gentoku were trying to fight off the creatures, while Soichi was working to keep Minister Himuro safe. "Help!"

Both Misora and Kasumi were being held by a yellow-colored monster with a blockhead.

Sento, seeing no other way to save the girls, makes a drastic decision.

Sento asks Taizan: "Minister Himuro, I can trust you, right?"

Taizan asks: "Why wouldn't you?"

With that statement, Sento tilts his head down and says: "This is the worst."

Banjo and Gentoku look at him as though he's gone mad.

 **(Kamen Rider Build OST – Born To Build starts playing)**

Sento pulls out from inside of his coat, the Build Driver.

He fastens the driver around his waist and pulls out the Rabbit and Tank Fullbottles.

He then says: "Now, let's begin the experiment."

Sento shakes the bottles in each hand, as the essences inside them make a rattling noise.

Physics equations, variables and symbols begin appearing out of thin air, confusing everyone present, not including Misora and her dad.

Sento places the bottles into the driver:

 **RABBIT!**

 **TANK!**

 **BEST MATCH!**

Sento begins to turn the lever on the side of the driver and two halfbodies emerge from the driver, which asks:

 **ARE YOU READY?**

Sento says: Henshin!

The halfbodies then snap together onto Sento, encasing him in some kind of protective armor, half blue and half red in color, a blue tank for his right visor and a red rabbit for his left. The driver announces:

 **FULLMETAL MOONSAULT!**

 **RABBIT! TANK!**

 **YEAH!**

Sento declares: "I've found the winning formula."

Taizan remarks: "Incredible!"

Gentoku gasps: "Impossible!"

Banjo exclaims: "Awesome!"

Sento uses the spring on his left rabbit leg to propel himself forward and at the monster, knocking it over. He tells the now-freed Misora and Kasumi: "Hurry you two, get back to the others!"

The girls do what Sento tells him and go over to what the rest of their group were.

Sento turns his attention back to the blockhead, who is now back on its feet.

He punches and kicks the monster, intercepting its attempts to hit him and countered in kind.

Once the monster was tired and low on energy, Sento turned the lever on the driver once again and it announces:

 **READY GO!**

 **VOLTECH FINISH!**

Sento jumps into the air, silding down an energy chart holding the creature in place and hits it with a powered flying kick. The driver finishes with:

 **YEAH!**

Sento proceeds to lay waste to the remaining four monsters in a similar fashion.

 **(Music stops playing)**

Sento removes the fullbottles from the driver and walks up to the group.

Banjo immediately said: "Sento, you were amazing! You took care of those monsters like it was nothing!"

Kasumi adds: "Jeez Sento, I knew that you were smart, but to think that you're capable of doing this?"

Gentoku probes: "How did you do this?"

Taizan is the one who answers that: "He's harnessed the power of the Pandora Box, haven't you Sento-kun?"

Sento smiles at that and says: "Don't you worry, Minister Himuro and Gentoku, I am a loyal citizen of Touto and will fight to protect love and peace!"

Taizan then asks: "What do you call that transformation?"

Sento replies: "Call me Kamen Rider Build!"

All the while, no one saw the look of eagerness that was present on Soichi's face.

* * *

 **Back at Nascita Café**

The refrigerator door of the café was opened by Sento, to reveal a secret passageway leading to a laboratory. Sento, Misora and Soichi lead Banjo and Kasumi to Sento's personal lab.

Banjo and Kasumi are shown the video that Sento's parents left for him.

Banjo asks: "So, what we saw just earlier was your quirk, Nebula Gas? And you use it to access and power the Rider System?"

Sento confirms this: "Basically."

Kasumi comes to a decision and asks: "Sento, that offer that you had for Banjo, it wouldn't be you offering to give Banjo the Nebula Gas quirk so that he can become a hero, would it? Kasumi is smiling at Sento like she has outsmarted him.

Sento, surprised by having been caught says: "No way!"

Misora interjects: "I think that giving Banjo Nebula Gas is a great idea! He's a naturally great fighter and with a quirk, he'll be that much stronger!"

 **(Kamen Rider Build OST – Be The One starts playing)**

Sento makes the offer: "So what do you say, Banjo? Do you and Kasumi want to join the Build crew?"

Banjo asks: "What's the Build crew?"

Soichi reponds: "It's the name of the hero agency that Sento and Misora want to establish. The Touto Institute of Advanced Matter Physics would help with support and funding. Of course, you would have to take the hero entrance exam for UA like Sento and Misora plan to!"

Kasumi catches that Soichi mentioned that Misora would also be taking the entrance exam: "Wait Misora, you have a quirk?"

Misora pulls out her own Build Driver as well as a white dove bottle and a pink plane bottle and explains: "I had Sento and my dad conduct the Nebula Gas Test on me so that I could be a hero too! I'm Kamen Rider Rescue!"

Misora then makes a fighting pose and punches the air, startling Banjo and Kasumi a little.

Banjo looks at Kasumi and asks: "Can I, Kasumi?"

Kasumi tells him: "Of course you can, with a quirk, you can be an amazing hero! I'll support you guys all the way, I plan on applying for UA's support course so I can help the agency in my own way!"

Sento says: "Welcome abroad, Banjo and Kasumi! Let's be heroes!"

Soichi walks out of the lab, as the four kids are engaged in a group hug.

 **?**

A mysterious bat-like figure is shown sitting in a throne, overseeing experiments being conducted by scientists in hazmat suits. The figure only says: **"Let us prepare for war."**

 **(Music stops playing)**

 _Name: Sento Kiryu_

 _Quirk: Nebula Gas_

 _Name: Ryuga Banjo_

 _Quirk: (Nebula Gas Next Chapter)_

 _Name: Misora Isurugi_

 _Quirk: Nebula Gas_

 _Name: Kasumi Ogura_

 _Quirk: Quirkless_

 _Name: Night Rogue_

 _Quirk: Nebula Gas_

* * *

 **A/N: And there we are! Sento has finally begun his story as Build, made some new friends, and is walking down the path to becoming a hero!**

 **Next chapter will see Ryuga getting accustomed to his new quirk, Kasumi learning all that she can to help our heroes, Sento, Misora and Banjo prepping for their entrance exam, and meeting the devil's scientist as well as a mechanic covered in Grease.**

 **I don't really have a timeframe for the next chapter, so I will try to write and upload it as soon as I am able.**

 **Thanks as always and I hope you all find yourselves well! DarkAbyssBreak out!**


	5. Another Genius and a Greased-up Mechanic

**So, here we are with yet another chapter of Be The One For All. After this and one more chapter, the story will return to Deku's, or the Hero Academia point of view until the two converge and this tale can truly begin to go forward. As this is a fanfiction, moreover a crossover fanfiction, I'm going to take some liberties with regard to certain events. For example, I'm not going to have the Hokuto trio appear in this story's version of the Build cast. I never really liked them and I just don't want them here. However, I am going to have Kazumin have a different motivating factor that could make this version of Grease unique.**

 **This chapter will have a lot of, pun intended, build up! We'll see Sento, Ryuga and Misora work at raising their hazard levels for the entrance exam they'll have to take in 3 years time. Banjo and Kasumi will also foster and improve their budding friendship with Sento and Misora. As those who have watched Build may know, Banjo isn't exactly the smartest guy around, so Sento and Kasumi will help to tutor him on the material that will show up on the written portion of the exam.**

 **Now, my version of Takumi Katsuragi will be different from the canon. Seeing as Shinobu and Kyoka are written here as Sento's parents, I've elected to make Takumi an orphan. His appearances will be quite significant, I assure you. Takumi is just as intelligent as Sento, albeit as bit more serious.**

 **Also, the Faust organization will ratchet up their experiments to create more smash monsters, for what purpose, who can say?**

 **Anyways, I do not own Kamen Rider Build or My Hero Academia, or any of the soundtracks mentioned.**

* * *

 **Another Genius and a Greased-up Mechanic**

 **Touto Institute of Advanced Matter Physics**

It had been 3 days since Banjo and Kasumi agreed to Sento's proposal. That same day, Banjo underwent the Nebula Gas Test at the Institute, as Sento had learned how to perform the experiment from his parents research. Kasumi was there with Banjo during the whole procedure, with him emerging from the chamber, now possessing a quirk.

 **Three days ago**

 _After Banjo came out of the chamber, Sento asked the couple: "So, are you guys curious as to what bottle Banjo will produce?"_

 _The pair look at Sento mildly confused by the question._

 _Sento takes notice of this and clears up: "After my parents gave me the Nebula Gas quirk, they took a sample of my essence. As it turned out, I had two essences produced as a result of the experiment. Those being the Rabbit and Tank fullbottles you both saw me use the other day."_

 _Kasumi asks him: "How does that work exactly?"_

 _Sento smiles and says: "Follow me, and I'll show you both."_

 _Sento led Banjo and Kasumi to a large microwave machine in the next room over, where Misora was waiting for them._

 _Misora waved at the group and said: "Hi there, everybody! So, did you finish the test?"_

 _Sento replied: "Yes we did, Misora. My scanner tested Banjo as being positive for the Nebula Gas quirk._

 _She responds: "Wonderful, now I can do my part!"_

 _Banjo inquires: "Uh Misora, What exactly are you gonna do?"_

 _Misora tells him: "When I got the gas test done with my dad and Sento close by, a golden bracelet emerged from the Pandora Box and fixed itself to my wrist." She holds up her left arm, revealing the item in question._

 _Kasumi asks: "What is it?"_

 _Misora says: "From what Sento and my dad have studied, it seems to be an object of extraterrestrial origin similar to the Pandora Box. Also, it seems to help the purifying machine purify bottle essences much quicker."_

 _Banjo exclaims: "Well, what are we waiting for! Let's find out what I got!"_

 _Sento then approached Banjo with an empty fullbottle and told him: "This empty bottle will absorb part of your essence, now changed as a result of you possessing Nebula Gas." Sento points the bottle at Banjo, and a blue gas begins leaving Banjo and entering the now occupied fullbottle._

 _Sento marvels: "This is the best! Now, Misora darling, if you would?"_

 _Misora kindly responds: "Of course, Sento dear!" as she takes the bottle from Sento and places it in the microwave slot._

 _Banjo and Kasumi both smile at the amorous couple's interaction._

 _Misora then enters the door on the left side of the machine and tells everyone: "No peeking!"_

 _A few hours later, the microwave beeps, indicating that the bottle is ready._

 _Sento notices this and gestures for Banjo and Kasumi to come over._

 _Sento opens the microwave door and pulls out a blue fullbottle with a dragon on it. He excitedly says: "Wow, so you got a Dragon fullbottle! Makes sense with how strong you are!"_

 _Sento hands the Dragon fullbottle over to Banjo, who was looking it over along with Kasumi, very happy until he remembered something and asked Sento: "Hold on a minute, you got a Rabbit and Tank bottle, and Misora got a Dove and Plane bottle, so why did I get only one bottle?"_

 _Kasumi adds in: "Yeah, this is very curious."_

 _Sento tells them: "My parents research revealed that the empty fullbottles can extract a bit of the essence of someone with Nebula Gas and create bottles that are best suited for them. My dad found out that very rarely, a person with Nebula Gas will produce a single bottle instead of two. This means that the single bottle's essence is very potent and a second bottle to match isn't necessary."_

 _Sento reveals a gold-colored bottle in his hand with a lock on it and continues: "This Lock fullbottle is the inorganic match to your Dragon bottle, however, as your Dragon bottle is highly potent, transforming using this best match would result in you only being able to remain transformed for 1-2 minutes. This is due to the Dragon bottle overpowering the Lock bottle."_

 _Banjo looks dejected because of Sento's words until the Genius said: "Of course, that would be the case if you didn't have Touto's resident genius on your side!" Sento pressed on: "I'll create a device that will allow you to transform using the Build Driver and your Dragon bottle! You'll be just as powerful as Misora or I when we use our best matches!"_

 _At this, Banjo jumps in the air with his fist raised up high, and says: "Alright! Thanks Sento, you're the best!"_

 _Kasumi also chips in: "We are so thankful, Sento!"_

 _Sento tells them: "It's my pleasure."_

 _Misora then steps out of the machine, looking very tired and haggard. She dragged herself towards the bed in the lab room and proclaims: "I'm tired… Hungry… Sleepy… Want my money…"_

 _Sento seeing his girlfriend all tuckered out, offers: "Then, how's about I make you a sandwich and bring you your favorite drink, a strawberry milkshake?"_

 _Misora answers tiredly: "That sounds good, love you Sento."_

 _Sento happily replied: "I love you too, Misora."_

 _The young genius turns to his friends and tells them: "After purifying a fullbottle, Misora exhausts most of her energy and stamina, and has to rest for a while to recuperate."_

 _The genius physicist looks at his friends and asks: "Do you two want to grab some lunch with me? After we're done eating, I plan on making Banjo's transformation device."_

 _Kasumi answers for the both of them: "Why thank you, Sento! Ryuga and I would love to join you for lunch!"_

 _Banjo follows with: "Yeah man! After that gas test, I'm running on empty, so I could go for a bite!"_

 _Sento smiles at the two and says: "Ok then, both of you follow me over to the Institute's kitchen!"_

* * *

 _The trio make their way over to the Institute's kitchen to get some lunch. They arrive to an enormous room, filled with several refrigerators, ovens, sinks and cupboards and all of the things that would be in a kitchen._

 _Banjo and Kasumi are astounded by the fancy facility and both feel a little out of place._

 _Banjo politely asks Sento: "Are you sure that we can be here, Sento?"_

 _Sento says: "Of course! I am the head of the Institute and the both of you are here as my guests! Also, I plan to have the both of you join the Institute if you accept. Banjo would be our tester, as they are many inventions that will only produce results from being handled very intensely and Banjo is a very strong individual."_

 _Banjo puffs out his chest at the compliment._

" _Kasumi, on the other hand, has a very good memory and superb organizational skills. I could see her as our secretary, handling the ins and outs of the Institute's paperwork."_

 _Kasumi replies: "Of course we'll join the Institute Sento! This place is one of the most innovative and successful organizations in all of Japan! We accept and promise to do our best and help the Institute!"_

 _Banjo includes: "Sento, you've already done so much for me, man. You think that I'd say no at this point? Count us in!"_

 _Sento invites them: "Welcome to Touto Institute, Banjo and Kasumi!"_

 _As they are about to get their food, a young man wearing a white lab coat, with lab googles hanging from his neck, walks into the kitchen and notices the 3 other people in the room, especially Sento._

 _The person addresses Sento: "Director Kiryu! How are you doing today, sir?"_

 _Sento answers: "I am feeling great, Takumi! Thank you for asking."_

 _Sento turns to Banjo and Kasumi: "I would like to introduce the both of you to Touto Institute's lead scientist, Takumi Katsuragi!"_

 _Banjo and Kasumi greet Takumi politely._

 _Takumi questions curiously: "What are these two doing here in the facility's kitchen?"_

 _Sento informs him: "They are my friends and are here as my guests. Also, I just hired them as the newest editions to the Institute's staff! Ryuga Banjo here, will serve as our invention tester and Kasumi will be our new secretary!"_

 _Satisfied with having his question answered, Takumi tells the couple: "Well, I hope that we can except great things from you two. Director Kiryu has something of an eye for talent."_

 _Kasumi tells Takumi: "Sento has been very kind and hospitable to us. We hope that we can be of help to him and the Institute."_

 _Banjo says: "Yeah! He's a good guy!"_

 _Hearing them say these nice things about Sento made Takumi grin a little: "Well, I wish the best for you both, I'm sure that I'll see you later." Takumi turns to Sento and says: "Director Kiryu," Sento interrupts him: "Takumi, how many times have I told you, you can call me Sento." Takumi looks a bit surprised, but then continues: "Right, Sento. Should you need me, I'll be in the inventions lab, working on my latest project."_

 _Sento assures him: "Don't worry, Takumi! Should I need you, I'll be sure to contact you."_

 _With that, Takumi then bids the trio farewell and returns to his work._

 _After Sento, Banjo and Kasumi returned to the lab with their food, Sento left Misora's sandwich and her milkshake on the table next to her bed._

 _They sit down to lunch and cleaned up their mess. After such an eventful day, Banjo and Kasumi decided to go home._

 _Sento suggested: "The Institute has a self-driving car that we could use to drop you guys home, why don't use it?"_

 _Tired and seeing the appeal at the offer, the couple accepts Sento's decision._

 _10 minutes after the trio left the Institute in the car, the engine suddenly begins to stall. Sento notices this and the car parks itself off of the road._

 _Sento inspects it and says: "This was one of the prototype cars that was never fully completed. I should've been more attentive before we left."_

 _Banjo says: "Hey bro, these things happen."_

 _A passerby happens to notice their dilemma and offers to help. He asks: "Hey, do you guys need a hand? I happen to be a mechanic!" The person in question appeared to be about their age, with brown hair and wearing a brown hooded fur parka._

 _Sento accepts the help: "Please, do what you can."_

 _The mysterious mechanic gets right down to business._

 _About 5 minutes later, the car's engine is purring as though it were new._

 _Sento and company were very impressed by the speed and effectiveness with his work._

 _Sento pressed the stranger: "I would like to know the name of the person who manage to save me a trip to the garage."_

 _The boy answered: "Name's Kazumi Sawatari, originally from Hokuto!"_

 _At this, Kasumi recoiled a little and verified: "You're from Hokuto?"_

 _Seeing how she reacted, Kazumi rubbed his hand on his neck and told her: "Yeah, I bet you didn't expect to see a Hokuto native around Touto, huh?"_

 _Banjo calms Kasumi down and explains to Kazumi: "Sorry man, my girlfriend and I have had some run-ins with some bad people who were from Hokuto and Seito, so you'll have to forgive us if we're a bit surprised."_

 _Kasumi tells Kazumi: "I'm so sorry, thank you for helping us! Might I ask what you are doing here so far from home?"_

 _Kazumi explains: "See, my family's farm was running out of money to keep up with the payments and our land became infertile due to the weather. So, I decided to use my skills as a mechanic to find work here in Touto. Don't worry!" Kazumi pulled out his wallet and presented a permit "I'm here in the country legally, I applied for Touto's dual citizenship program and finally got accepted last week._

 _Sento, Banjo and Kasumi felt sympathetic of Kazumi's issue until Sento had an idea._

 _He asked Kazumi: "Where are you staying, Kazumi?"_

 _At the sudden question, Kazumi looks a bit embarrassed and says: "The Touto Temporary Housing Center."_

 _Sento informs him: "Not anymore you're not, you are coming with me to set you up with someplace to live."_

 _Kazumi is stunned by the sudden proposal and asks: "Really?"_

 _Sento introduces himself: "My name is Sento Kiryu, Director of Touto's Institute of Advanced Matter Physics."_

 _Kazumi is caught by surprise, as he had just helped out one to Touto's most influential citizens._

 _Sento continues: "You managed to fix one of my companies prototype engines in 5 minutes, I want that skill put to work for my company. Kazumi Sawatari, will you come work for me as a mechanic?"_

 _Faced with such an incredible offer, Kazumi suddenly drops to his knees in tears and asks: "Really? You want me to work for you?"_

 _Sento smiles and repeats: "Yes Kazumi, what is your answer?"_

 _Kazumi stands and shakes Sento's hand: "Hell Yeah!"_

 _Sento gives Kazumi the Institute's business card and tells him: "The address on there is where our main building is located and the phone number is there if you decide to call in first."_

 _Kazumi tells him: "I'll pay a visit tomorrow! Thank you!"_

 _Sento simply responds: "You're welcome."_

 _After the trio parted ways with Kazumi, Sento drove the pair home._

* * *

 _The following day at noon, Kazumi was sitting in the Institute's reception area, waiting to see Sento about the job offer. Sento and Misora step through the door to greet him._

 _Sento welcomes him: "Good afternoon, Kazumi! I see you're here to discuss the mechanic position that has just opened up!"_

 _Kazumi takes notice of Misora and asks: "Uh Sento, is she your girlfriend?"_

 _Misora gives Kazumi a kind smile and answers: "That'd be me, Misora Isurugi!"_

 _Kazumi bows in respect and says: "Pleasure to meet you!"_

 _Misora does the same and say: "You too!"_

 _Sento then begins to elaborate: "Now Kazumi, from what I saw of your skills yesterday, I can tell that you are quite the gifted mechanic. As such," Sento took out a blank slip of paper and began to write a number on it "Do you believe that this will be sufficient pay for your services?"_

 _Sento hands Kazumi the slip and Kazumi is bewildered. He stared at the paper and then at Sento, multiple times to confirm he wasn't see things._

 _Kazumi shakily asked: "Sento, is this what I'll be making per year?"_

 _Sento answers: "No, that will be your weekly salary."_

 _Kazumi begins to openly cry and Sento and Misora, worried for the boy, each place a hand on one of his shoulders to steady him. Sento asks: "What's the matter? Is the figure too small? That is the starting amount that we pay all of our employees?"_

 _At this, Kazumi hugs Sento and explains: "With this much money, it'll only take me about a month to make enough to pay off my family's farm's debt! Sento, I don't have the words, man!"_

 _Sento hands Kazumi a new-looking wrench and tells him: "If you lack the words, then show me through your effort, Kazumi!"_

 _Kazumi correct him: "Kazumin, call me Kazumin, that's what my friends call me. You too, Misora!"_

 _The couple say together: "Ok, Kazumin!"_

 **Present Day**

Kazumi was fitting in right at home in the Institute, with even Takumi requesting Kazumi's help with mechanical issues on occasion.

Sento, Misora, Banjo, Kasumi, Kazumi and Takumi all find themselves in Sento's Institute lab site. Sento pulls from his workshop, the completed Cross-Z Dragon for Banjo and hands it to him.

Banjo marvels at the device and asks: "Is this the device you were making for me?"

Sento replies: "Just finished it last night, also careful with it Banjo, it might burn you."

Banjo asks: "What do you mean by tha… ouch!"

The Cross-Z Dragon lightly burns Banjo's right hand for holding it too tightly.

Kasumi then gently picks up Cross-Z Dragon and pets it: "Aw, you just wanna play, don't you?"

Kasumi asks the Cross-Z Dragon: "Can you help my Ryuga here? He needs your help if he wants to achieve his dream of becoming a hero."

Cross-Z Dragon decides to do what she asked and flew into Banjo's hand.

Banjo asks Sento: "How do I transform?"

Takumi is the one who answers him instead: "You merely need to place your Dragon fullbottle into the Cross-Z Dragon, then you tuck in its head and tail, and finally, place it into the Build Driver and turn the lever."

Sento remarks: "Correct! I couldn't have said it better myself, Takumi."

Takumi is visibly happy at having impressed Sento.

Banjo says: "Ok! Let's try this out!"

Everyone takes a few steps back as Banjo prepares to transform.

Banjo shakes the Dragon fullbottle and puts it in Cross-Z Dragon. He folds in the head and tail and places the adapter into the Driver. The Driver announces:

 **WAKE UP!**

 **CROSS-Z DRAGON!**

Banjo then turns the vortex lever and the Driver produces two blue halfbodies and asks:

 **ARE YOU READY?**

Banjo replies: "Henshin!"

The Driver responds:

 **WAKE UP BURNING!**

 **GET CROSS-Z DRAGON!**

 **YEAH!**

Banjo is standing there, fully clad in the Cross-Z Dragon armor. He has 2 blue dragon shaped visors and there is distinctive shoulder armor covering him.

Everyone is amazed and happy for Banjo as he begins freaking over the fact that he is now a Kamen Rider.

He approached Kasumi while he is transformed and asks her: "What do you think?"

She hugs Banjo and says: "My hero."

Banjo reciprocates the hug and everyone present smiles at the cheerful atmosphere.

Sento claps his hands together, interrupt the proceeding and says: "Now that Banjo has successfully transformed, let's go celebrate! We should all go to Nascita! After all, today is March 1st, and from Kasumi told me, today is Banjo's birthday!"

All of a sudden, a happy birthday sign drops down from the lab entrance and everyone but Banjo launch streamers and yell: "Surprise, happy birthday Banjo!"

Banjo just says: "Aw, thanks guys!"

Kazumi, who's new to the group asks: "What's Nascita?"

Misora answers: "You'll find out!"

Takumi asks: "I'm invited too?"

Sento looks at Takumi: "Takumi, you've been a big help to the Institute ever since I saw you at the orphanage." Takumi remembers that fateful day, when Sento brought him to the Institute. "That's why not only are you invited to come celebrate with us, I'm appointing you as acting head of the Touto Institute of Advanced Matter Physics!"

This news catches Takumi totally off guard: "Sir! Are you stepping down?"

Sento answers: "You know that I plan to take UA's entrance exam along with Banjo and Misora, right?"

Takumi nods at this.

"Well, I'll need someone that I can trust to run the place while I'm out being a hero, at least until I obtain my Pro Hero License and can turn the Institute into a hero agency as well. I pick you. You've shown me time and time again that not only are you willing to do the hard work, you have a genuine love for science that rivals even mine! There is no other choice."

Takumi places both arms at his sides and says: "I won't let you down, Sento!"

Sento tells him: "I know you won't."

 **Nascita café**

About half an hour later, the whole gang arrives at a closed Nascita.

Misora pulls out her house key and opens the door.

They all enter to find Soichi waiting for them, with the most delicious looking dragon-themed cake they ever saw, a mountain of snacks and plenty of drinks. Banjo blew out the 12 candles on his cake and the party began. Banjo challenged Kazumin to an arm wrestling contest, Misora and Kasumi were discussing fashion and their boyfriends, and Sento and Takumi were engaged in a conversation about quantum physics. Soichi was throwing darts and keeping the place in order. They all partied well into the night, everyone present thinking of what the future would have in store for them.

* * *

 **Three Years Later**

One week before the entrance exam, we see Kamen rider Build, Cross-Z, and Rescue sparring against each other. Their Hazard Levels had steadily increased over the years and now Sento and Banjo had reached 3.5, while Misora had a 3.3 level. Kasumi and Takumi were observing the training, analyzing for ways to improve the routine so that the 3 are at their best.

After the 3 riders finished their training for the day and powered down, Kasumi approaches Banjo: "Ryuga, we need to finish your studying for the written exam!"

Banjo sulks: "Do we really need to study anymore, whenever I'm not training or sleeping, I'm studying with you and Sento."

Sento jokes: "Banjo, with the way that you retain information, you need to keep informed up until exam day so that you can barely pass the written portion. That way, you can dominate the practical exam!"

Banjo resigned himself to his fate: "Ok you two, let's study some more while I'm still awake."

Banjo is shown sitting at a desk, answering practice questions, reading through hero material, and answering Sento and Kasumi's questions.

Sento asks Banjo: "Who is the number 1 hero in Japan?"

Banjo quickly answers: "All Might, duh!"

Kasumi asks: "What is the level of education needed to take the exam?"

Banjo responds: "Middle school completed!"

Both respond: "Correct!"

30 minutes later, Banjo finishes his studying and Sento and Kasumi congratulate him on a job well done.

Sento tells him: "At this rate, you'll be a hero in no time!"

Kasumi nods in confirmation.

Misora calls to Kasumi: "Hey Kasumi! I could use some help with the math portion, could you lend me a hand?"

Kasumi smiles at her bestie and says: "Sure thing, Misora-chan!"

Meanwhile, Sento and Banjo sit down and Sento reminds him: "So Banjo, the exam is exactly one week from today, how are you feeling?"

Banjo tells his genius friend: "Honestly? I'm really nervous about the whole thing, but if I've got you, Kasumi and the others by my side, I feel like I can't lose!"

Sento smiles at his friend and says: "There you go, your most valuable trait is that burning determination of yours. As long as you have that, you'll be ok even when we're not around."

The two exchange a fist bump and Misora and Kasumi witness this.

Misora comments: "The friendship between boys, I'm almost jealous." she says jokingly.

Kasumi adds: "I'm so happy that Ryuga's found a true friend in Sento and the rest of the crew. I'm also happy that you're all my friends too!"

Misora hugs Kasumi and tells her: "That's right, and we're gonna stay that way!" Misora breaks the hug and holds out her pinky finger "That's a promise!"

Kasumi links her pinky with Misora's and the two giggle.

 **UA High School**

Sento, Banjo and Misora are gathered around with the other participants, awaiting the signal to begin the practical portion of the exam.

Banjo sighs in relief: "I managed to pass the written part!"

Misora assures him: "We knew that you could do it!"

Sento adds: "You may not be a genius, Banjo, but you are far from dumb."

Banjo grins at his friends and says: "Thanks, you two! Now, let's kick this practical test's butt!"

Sento brings up: "Do you both remember our strategy?"

Misora answers: "Teamwork!"

Present Mic shouts: "Start!"

The practical exam had begun.

* * *

 **Faust Hideout**

Night Rogue is shown ordering his subordinates to increase the output of Nebula Gas being pumped into their test subjects.

He is met with the sight of Blood Stalk, who showed up completely out of the blue.

Night Rogue demands: "What do you want, Stalk?"

Stalk baits the bat-themed villain: "You know, Sento Kiryu and his friends are currently taking the UA entrance exam. With their level of skill, they will pass and get into the academy."

Night Rogue presses Stalk: "This concerns me, how exactly?"

Stalk proposes: "You can take advantage of them being hero students to go about your plans to strengthen Touto and conquer the Hokuto and Seito regions!"

Night Rogue pulls out his Transteam Gun and removes the Bat bottle from it. The figure powers down, to reveal Gentoku Himuro, sporting an evil grin.

* * *

 **A/N: Sento and company are about to tackle the last part of the entrance exam and hopefully attend UA! The Faust organization will take bold action in order to fulfill their ambition.**

 **Next chapter will see the conclusion of the entrance exam, another encounter with Faust, a status update on the entire Build crew, and a meeting with Principal Nezu and a certain Symbol Of Peace!**

 **After next chapter, the focus will return to the Hero Academia side and from there, the Build crew will get involved with class 1-A. Expect lots of laughter, heartbreak, action, danger, and heroism.**

 **Until next time, DarkAbyssBreak out!**


	6. Building a Foundation

**Hey there viewers, DarkAbyssBreak back from the grind! After this chapter, the story will shift its focus back to Deku and the My Hero side. After which, UA will integrate the Build crew and the two stories will truly be as one. In this chapter, we'll witness Sento and his two partners take on the practical portion of UA's entrance exam. There will definitely be reactions from their fellow competitors, and UA's staff who are overseeing the exam from the viewer's box.**

 **Oh yeah, another point to address. So, I'm doing my own spin on this fanfic and I changed a lot of things regarding Kamen Rider Build, so let me break down what's different for future reference.**

 **One, Sawa won't be in the story. I'm having Kasumi take over her role on the team.**

 **Two, Sento and Takumi being different people. This was done so that I could use Takumi's character without it impacting Sento's too heavily.**

 **Three, no Hokuto Trio.**

 **Four, Gentoku's insanity was not amplified by Soichi triggering the Pandora Box, causing the Skywall to appear. Instead, similar to Bakugo, he is obsessed with a certain view of how he believed things should be done, and is beyond determined to carry it out.**

 **Which brings me to my last point, the Skywall incident didn't happen like it did in the Build series. Touto, Hokuto, and Seito are merely divided by regional differences and their respective governments.**

 **Now, let's see how the Build gang do in their exam!**

* * *

 **Building a Foundation**

 **UA High School**

Several of UA's combat training robots were swarming the test field, 1, 2 and 3 pointers were all over the place. Most of the examinees were scared out of their minds. They hadn't been sufficiently prepared for the assessment, more like they only learned what the schools were teaching for basic heroism and did little to no independent training of their own.

Which is why, when 3 bold students charged towards the robots, the rest of the group stared at them as though they were crazy.

"What are they doing?"

"That's nuts!"

"Those fools must have a death wish."

"Are they for real?"

Sento, Banjo and Misora ran full speed towards the robots, relieved about the fact that they were allowed to use their quirks freely and that the robots are repairable.

 **(Hamatora OST – Hikari starts playing)**

The 3 hero hopefuls pull out their Build Drivers and placed them around their waists. They think back to what they had discussed the day before.

 **Yesterday**

 _Kasumi and Takumi were finished assessing Build, Cross-Z and Rescue's power, speed, stamina, and adaptability. Takumi then motioned for the Kamen Riders to come to his workbench._

 _Takumi presents to the group: "The final step before you 3 undergo the exam tomorrow is to give you all your weapons."_

 _Banjo questioned: "Wait a minute, are Heroes allowed to use weapons?"_

 _Sento answered him: "As long as the weapon in question is within reasonable limits, it'll technically count as a support item, similar to our Drivers._

 _Misora said: "Like Snipe having his guns!"_

 _Takumi resumes his demonstration: "Speaking of guns, we'll start with Sento's weapon, the Drill Crusher."_

 _He holds up the Drill Crusher, which looks like a drill sword._

" _This weapon has two modes, sword mode and gun mode, making it a basic and versatile weapon for Build."_

 _Takumi hands over the weapon to Sento, who remarks: "I see that our collaboration resulted in quite the invention, huh Takumi?"_

 _Takumi agrees: "Yes Sento, it turned out great!"_

 _Turning over to Banjo, Takumi pulls out his weapon: "For Cross-Z, we have the Beat Crosser."_

 _This weapon looked more like a traditional sword than the last weapon._

 _Banjo holds up the Beat Crosser and slashs the air with it, commenting: "Wow, Takumi! This thing is really light and fast!"_

 _Takumi smiles and tells Banjo: "Your girl Kasumi helped with the development of the Beat Crosser, she really wanted to make sure that you'd have the best equipment come exam time."_

 _Banjo looks over at Kasumi, who winks at him and blows him a kiss, causing Banjo to blush brightly all over his face, covering it with his hands._

 _Sento, Misora and Takumi all laughed at the poor boy, amused that Kasumi could reduce Banjo to such a shy person._

 _Takumi addressed the last of the Kamen Riders, Rescue a.k.a Misora: "For you Misora, Sento personally worked on your weapon. Behold, the Reflex Bow!"_

 _Takumi holds out to Misora a silver bow, with a pink tip and highlights._

 _Sento takes over the explanation for Takumi: "Not only does the Reflex Bow have an incredible range, being able to shoot energy arrows from up to 60 meters away, it also has 4 different modes. The bow mode is the base mode, the reflex bow can change shape into a sword, staff and shield, depending on how you want to fight in a given situation. Sword mode is similar to my Drill Crusher and Banjo's Beat Crosser. Staff mode is when the bow extends into a staff that is equipped with a stun baton at both ends. Lastly, shield mode has the Reflex Bow fold in on itself into a circle, which emits plasma energy in a circular shape. This will be your best form of defense, aside from dodging."_

 _Misora is awed at all of the features and extras that Sento put in her weapon. She suddenly runs up to him, landing a kiss on his lips._

 _Sento is initially caught off guard, but then kisses his girlfriend back in kind._

 _The two broke the kiss and Misora, looking all teary-eyed said: "You're always do the nicest things for me, Sento. That's why I love you!"_

 _Sento holds Misora's hands and tells her: "I love you as well. We'll make you the world's greatest rescue hero, after all, you're Kamen Rider Rescue!"_

 _Banjo chose to voice an idea that Kasumi pitched to him a few days ago: "Hey guys, what do you say about going on a double date after the entrance exam? Kasumi is really interested and I think it could be fun!"_

 _Sento remarks: "Not a bad idea. Misora, what do you think?"_

 _Misora excitedly exclaims: "A double date with Banjo and Kasumi! Sounds like a good idea! Kasumi and I could get our nails done, check out all of the latest trends in the clothing stores, and lunch!" Misora gives Sento her best puppy dog eyes and ask: "Sento! Be a good boyfriend and say yes to the double date, please?"_

 _Sento grins at Misora and tells her: "Of course! Banjo and Kasumi are our friends, and an outing with them sounds like it could be interesting!"_

 _Sento turns to Takumi and tells the new head of the Institute: "Takumi, I sincerely appreciate all of the help that you've been giving us. You prove yourself to be more and more of an invaluable friend with every day!"_

 _Sento sticks out his hand for a handshake._

 _Takumi confidently grasps his friend's hand and says: "Right back at you, Build!"_

 _Sento eyes light up at being called his preferred hero name._

* * *

 **Back to present time**

Sento asks Banjo and Misora: "You guys ready?"

Both respond: "Yeah!"

Sento pulls out the Rabbit and Tank fullbottles and shakes them. He twists the caps on the top and places them into the Driver:

 **RABBIT!**

 **TANK!**

 **BEST MATCH!**

Banjo calls the Cross-Z Dragon, which arrives and flies into his hand. He shakes the Dragon fullbottle, twists the cap and put it in Cross-Z Dragon. Folding up the head and tail, he places the adapter into the Driver:

 **WAKE UP!**

 **CROSS-Z DRAGON!**

Misora pulls out the white and pink colored Dove and Plane fullbottles and shakes them. Much like Sento, she twists the caps on the bottles, then puts them in the Driver:

 **DOVE!**

 **PLANE!**

 **BEST MATCH!**

The 3 of them turn the Vortex Levers on their Build Drivers, which produce halfbodies held in place by the Snap Ride Builder. The Drivers ask:

 **ARE YOU READY?**

The 3 hero hopefuls yell: "Henshin!"

The 3 sets of halfbodies snap onto them and encase them, with the Drivers announcing:

 **FULLMETAL MOONSAULT!**

 **RABBIT! TANK!**

 **YEAH!**

 **WAKE UP BURNING!**

 **GET CROSS-Z DRAGON!**

 **YEAH!**

 **HIGHFLY CLEARSKY!**

 **DOVE! PLANE!**

 **YEAH!**

Sento and Banjo are transformed into Kamen Rider Build and Cross-Z.

Misora's appearance was very similar to Build, albeit with a few differences. She had a pink plane for her right visor and a white dove for her left. Her armor was half pink and half white and included a skirt. Kamen Rider Rescue was on the scene.

Build pulled out his Drill Crusher and began going to town on the exam bots. In a few seconds, he had already taken down 4 three-point bot, netting himself 12 villain points.

Similarly, Cross-Z was cleaning up shop as his boxing skills in tandum with the Rider system, resulted in him also clearing the field of 4 three-pointers. His Beat Crosser provided excellent slashing power and worked to counter any attacks the bots might throw his way.

Meanwhile, Rescue took down 3 three-pointer bots, earning herself 9 villain points. She took notice of 2 one-pointers making their way towards the unprepared examinees. Thinking fast, she pulled out her Reflex Bow in bow mode and shot 2 energy arrows, neutralizing the mechs.

Banjo comments on the display to Sento: "Hey bro, Misora's gotten really good at the combat part of being a hero! Must have been from all of those secret sessions you and her had together, huh?"

Sento turns to look at Cross-Z and simply tells him: "Partly, Misora's abilities are being showcased in full display and that comes right from her. When she wants to help someone," he thinks back to when he was in the Ambulance after his parents died, and Misora kept him from falling apart "she becomes more capable than anyone I know. It's part of why I love her."

Cross-Z points his finger at Build and states: "You said that so casually! Most people would be too embarrassed to say something like that!"

Build asks him: "Aren't you the same way with Kasumi?"

To that, Banjo pumps his fist to his chest and says: "Of course!"

Sento laughs and reminds Banjo: "Don't forget, the girls want to go on that double date later today after we're done here."

Banjo confirms: "Yeah, can't wait! It'll be cool for us to hang us some more!"

* * *

After 7 off the 10 minutes in the exam had passed, the UA staff in the viewing box were discussing the potential of the students. Principal Nezu, Eraserhead, Present Mic, Midnight, Snipe, Cementoss and All Might were deep in discussion about the candidates.

Principal Nezu commented: "Oh my! Those 3 in the armor are remarkable! To think that such talent and ability was hidden under our noses this whole time!"

Eraserhead interjects: "With the massive number of candidates that UA receives every year, those who have true potential often get overlooked."

Present Mic exclaimed: "Those 3 are rock stars! They're just mowing down the competition and look at how fast they took care of the faux villains! YEAH!"

Midnight added her two cents: "The one in the red and blue armor," she pulled out the file on Sento, "His name is Sento Kiryu, 15 years old and look at this, the former head of the Touto Institute of Advanced Matter Physics. He's considered to be a genius by all of Touto!"

Nezu caught the boy's last name and asked: "Kiryu?"

Snipe, taking note of the strange look on the principal's face asked: "Do you know the boy, Nezu sir?"

Nezu answered to those present: "Not personally, but I was on good terms with the boy's parents, Shinobu and Kyoka Kiryu, the former heads of the Institute."

Cementoss, confused by the use of past tense, asked Nezu: "You said was, does that mean that you no longer are?"

Nezu reluctantly said: "No Cementoss, what happened is that 8 years ago, a villain killed my two friends at the Institute, right in front of poor Sento."

All of the heroes in the room had adopted faces of horror and anger at the mention of the act.

All Might, who had been quite up to that point spoke: "Oh God. To think that boy at such a young age, was made to witness something that horrible and yet still pursue heroics." All Might stood up from his chair and raised his fist up high and said: "Now that's Plus Ultra!"

The somber atmosphere that had earlier permeated the room was suddenly gone, with All Might's show of righteousness. Even the usually distant Eraserhead cracked a small grin.

Nezu followed up: "Yes, that is true All Might. Personally, I've been keeping tabs on young Kiryu and he shows much promise. He appears to be just as brilliant as his parents, who were capable of discussion of high level subjects with yours truly!"

The teachers were stunned by the principal's words. To think that there were people out there who could contend with Nezu in terms of intelligence, even with his High Specs quirk? They all returned their gaze to Sento and his friends cleaning up what seem to be the last of the bots. If what the principal said was true, Sento could prove to be a valuable ally to society.

All Might then asked: "What about young Kiryu's two friends with him? They appear to be every bit as capable as him!"

Shota Aizawa, or Eraserhead, provided details: "The one wearing the dragon armor is Ryuga Banjo, same age as Sento and the girl. Get this, he was the former junior league boxing champion of Touto 4 years ago, but quit for personal reasons. Also, he was known to be quirkless.

Everyone was confused by what Eraserhead just said, the boy obviously had a quirk from what they were seeing out there.

Aizawa continued: "Lastly, the girl with them is Misora Isurugi, 15 years old. She's the daughter of Soichi Isurugi, the former astronaut who went to Mars and discovered the Pandora Box. Also, according to the biographical information, it seems that she is Sento Kiryu's girlfriend."

Nezu seems happy at this, that Sento still has people that he can depend on, even with what happened to him.

The principal turns his attention to All Might and asks him: "So, what do you make of UA, All Might? Seeing as you'll be on as one of our teachers next year?"

All Might gives Nezu and the rest of the staff a wide smile and tells him: "I like what I see, Nezu sir! I'm looking forward to helping to shape these young people into fine heroes in the future!"

Nezu then said: "Well, how about we wrap up this exam!" The mouse-bear looking person pushed a big red button, calling in the 0-pointer final boss.

 **(Music stops playing)**

* * *

Back to the exam field, Build, Cross-Z and Rescue just finished off the reminder of the robots. All of a sudden, tremors could be felt all across the area. The scared students were driving themselves crazy, trying to figure out what was going on. Meanwhile, Sento and his friends were looking out into the fake city and noticing something large was approaching them.

Sento told them: "Here we go, the last one is here!"

The 0-pointer faux villain robot emerged in all its glory, smashing through the fake buildings and sending debris and rubble everywhere. Immediately upon seeing the giant mech, the unprepared examinees turned around and proceeded to run away.

Most of them while running, took notice of how the 3 armored people who demolished the robots earlier were running towards the last bot instead. Many shouted out:

"Don't do it!"

"You're no match for it!"

"UA is crazy!"

"Stop!"

 **(Kamen Rider Kiva OST – Supernova starts playing)**

Sento commanded Banjo and Misora: "Ready for the finish?"

They confirmed: "Yes!"

Build, Cross-Z and Rescue began cranking the Vortex Levers on their Build Drivers while running towards the obstacle.

Sento said: "The rules of victory have been set!"

Banjo said: "No one can stop me now!"

Misora said: "The innocent will be saved!"

Their Drivers say:

Build

 **READY, GO!**

 **VORTEX FINISH!**

 **YEAH!**

Cross-Z

 **READY, GO!**

 **DRAGONIC FINISH!**

Rescue

 **READY, GO!**

 **VORTEX FINISH!**

 **YEAH!**

Sento and Misora jump into the air, with a white energy chart manifesting and them delivering a flying rider kick while riding the chart to the robot.

Banjo had a dragon made of energy surround him, then he jumped at the robot along with Sento and Misora, with the dragon trailing behind him.

The 3 Kamen Riders delivered a triple rider kick, obliterating the robot as they kicked straight through the mech and as they landed on the other side, multiple explosions erupted all over it and it broke apart.

 **(Music stops playing)**

Present Mic steps out as the last second counts down and he yells: "Time's up!"

The cowardly examinees could only look down as none of them had earned a single point and didn't even try out of fear.

Build, Cross-Z and Rescue disengaged their transformations and gave each other a triple high five with Misora proclaiming:

"We did it!"

Sento smirked at his girlfriend and asked: "Was there ever any doubt?"

Banjo chooses to answer that: "Nope! I knew we could do it!"

* * *

Just then, an elderly lady wearing a nurse's outfit walked up to the examinees and asked: "Okay, is anybody hurt?"

Most of them looked away in shame and replied: "No."

Recovery Girl was confused. Most of the time, there are at least one or two students who incurred injury due to the exam. She turns her attention to Sento, Banjo and Misora, noticing that the 3 of them were standing by the remains of the 0-pointer.

She approached them and Misora instantly notice her: "Oh my God! It's Recovery Girl! I can't believe it! I'm a huge fan, Ma'am!"

Recovery Girl was flattered by Misora and said: "Thank you, dearie."

Misora pulled out a pen and some paper, asking: "Do you think I could get your autograph, please!"

Recover Girl take the pen and puts down her name on the paper saying: "Sure thing young lady, after all, it's been a while since I've seen such capable students handle themselves so well! Not since All Might took his entrance exam!"

She handed Misora the autograph and Misora says: "Thank you! I'll put it someplace safe!"

Recovery Girl asks: "Why don't you introduce me to your two friends there?"

Misora does just that: "Right!" She links her arm with Sento's and says: "This here is my boyfriend, Sento Kiryu!"

Recovery Girl remembers that she read the newspaper article about Sento taking over the Institute. She asks him: "Aren't you that Kiryu boy who took over the Touto Institute? Why are you taking UA's entrance exam?"

Sento looked at the old woman and told her: "Yes, I am Sento Kiryu. As to your second question, I appointed a dear friend of mine to run the Institute during my absence, sharing the ownership with him. His name is Takumi Katsuragi and he is just as capable as me."

Satisfied by Sento's thorough answer, she turned to Banjo and asked: "And you boy, aren't you the former junior league boxing champion from a few years ago?"

Banjo explained to her: "Yep that's me! Ryuga Banjo!"

Recovery Girl looked down at her wristwatch, taking notice of the time and that she had other matters to see to. She bid the trio farewell: "I have to be going now dearies, but I be sure to see you 3 at UA come the next semester!"

Recovery Girl walked off to deal with the tasks that remained for her to finish.

Just as the 3 riders were about to leave, the loudspeaker rang and Nezu's voice could be heard: "Sento Kiryu, Banjo Ryuga and Misora Isurugi! Please report to the viewing box, UA's staff would like to have a word with you 3."

The 3 looked at each other and Banjo said: "Let's go see what they want."

* * *

The 3 students found themselves in the viewing box, per Nezu's request.

In front of them were some of Japan's finest heroes. Principal Nezu, Eraserhead, Present Mic, Midnight, Snipe, Cementoss, and All Might.

Banjo reacted as expected and freaked out: "Look guys! It's All Might! And Snipe! Everybody here is a pro hero!"

Sento put his hand on Banjo's shoulder and told him: "Calm down, Banjo. Let's see what they want with us."

Nezu chose to then address the 3: "Thank you for that Sento! Your friend seems to be quite excitable. Hopefully, that means that he has just as much energy to put towards heroics!"

The principal decided to get straight to the point: "I am curious though, the 3 of you were registered as quirkless before applying for the entrance exam, and your earlier display confirms that the 3 of you do indeed possess quirks. So, could you please enlighten me as to how this is possible?"

Misora spoke up: "Principal Nezu sir? We'd be glad to tell you all, but you must promise that what we tell you won't leave this room."

Eraserhead interjects: "Do you 3 know something so important, that you would make us promise this before telling us?"

Sento comments: "Very preceptive, Shota Aizawa. Yes, the knowledge that you all want is so important that only I, Banjo, Misora, 3 of our friends, my legal guardian who is Misora's dad, and Prime Minister Taizan Himuro and his son know, 9 people total."

Hoping that revealing some information would encourage Sento to do the same, Nezu decided to tell Sento the truth: "Sento, I was very close friends with your parents, Shinobu and Kyoka Kiryu."

Sento's expression reveals a surprised look: "You knew my parents?"

Nezu nods and continued: "Oh yes! We would discuss all manner of subjects, math, science, culture, law, if it existed, we spoke about it." Nezu shed a few tears and resumed: "When I heard that your parents were murdered by a villain, I was tempted to leave my post in order to find the one responsible and see to it that they would meet justice. Sadly, my responsibilities as UA's principal were too immense to drop at a moment's notice, and so I entrusted the task to the police."

Sento informed Nezu: "The murderer's name is Blood Stalk."

The eyes of all of the pro heroes present widened and Nezu remembered: "That's right, you were there that fateful night, Sento. Still, the fact that you got a name out of the criminal is most fortunate. This could mean that we can find him someday soon."

Sento agrees: "I hope so too, sir."

Misora holds his hand and Banjo taps his fist on Sento's shoulder.

Present Mic starts bawling: "I can't believe that something so sad had to happen! Poor kid!"

Midnight offered her sympathies: "That's a raw deal, I'm so sorry Sento."

Snipe comments: "Still, you inherited the Touto Institute from your parents and kept their work alive! You're contributing to society and continuing their legacy."

Cementoss praised the boy: "It does my heart good to hear that the young people of today have such fortitude!"

Eraserhead spoke up: "If principal Nezu vouches for your ability, I suppose that the 3 of you have potential." He grins at the riders "I look forward to your futures."

Finally, All Might said his piece: "Young Kiryu. It is truly tragic what befell your parents those many years ago. However! I am pleased to see that the event did not dim the light in your heart and that you want to be a hero! We need more people like you!"

Sento thanks the number one hero: "Thank you, All Might!" He turns to the other heroes "Thank you everyone!"

Sento decides to tell the heroes: "Okay, you've all convinced me. I'll tell you all the secret behind our quirk."

Nezu perked up at what was said: "I'm sorry, did you say our quirk?"

Sento confirms this: "Yes, our quirk."

Eraserhead speculates: "So, the three of you share the same quirk. How is this possible?"

Sento explained to the pro heroes all the details pertaining to his parents' experiments with the Pandora Box, the Nebula Gas, the Rider System, everything.

All Might then asked: "So, the three of you share this Nebula Gas quirk?" The quirk reminded him of One For All, with the similarity that multiple people can possess it.

Sento confirms: "Correct, All Might."

With everything now out in the open, principal Nezu decided to conclude the meeting: "Well, I appreciate that you opted to tell us about your discovery Sento. We swear that we will keep quiet in regard to this quirk, only speaking about it with your permission."

Misora bowed and said: "We appreciate that very much, sir!"

Nezu smiled and told her: "No problem, young lady!"

Before sending them on their way, Nezu told them very casually: "Oh by the way, the 3 of you passed the entrance exam, congratulations!"

All of the pro heroes clapped for the newly admitted first years of UA.

Sento and the others hugged each other and cried a little. They were going to their dream school, they were going to be heroes.

* * *

The double date had been wonderful. The two couples went to Touto Mall, and had a fantastic time. Sento and Banjo beat the girls at laser tag, and they gladly held their girls' many shopping bags. The outing ended with the 4 of them grabbing something to eat at the food court. Sento had some grilled fish over rice, Banjo and Kasumi had chicken teriyaki, and Misora had some sushi. Of course, Sento paid for everything, as his parents left him a fortune and he was more than willing to spend the money on Misora and their friends.

After the date was over, Banjo and Kasumi thanked Sento and Misora for the fun day and walked home. As Sento and Misora arrived at Nascita and were about to go inside, Sento paused at the entrance. Misora took notice and asked: "Sento, are you ok?"

Sento smiled and told her: "I'm just gonna stay out here for a bit, get some fresh air before I turn in."

Misora stood on her toes and pecked Sento on his cheek and said: "Alright then, come inside soon ok?"

As Misora went inside their café/home, Night Rogue jumped down from a nearby building in front of Sento.

Sento, wary of the stranger asked him: "Who are you, and why were you following us?"

The figure ignores him and says: "Sento Kiryu, your genius is unrivaled and could be put to good use in service of Japan. Come join the Faust organization."

Sento responds: "I've heard of you, Faust is a terror group that performs unethical experiments on people, turning them into Smash!"

Night Rogue says: "That is so we can create the perfect being."

Sento retorts: "Perfect being? No such thing."

The bat-like armored figure sighs: "So you won't accept my invitation?"

Sento tells him: "I plan on becoming a hero who can protect love and peace!"

Night Rogue grows bat wings and tells Sento: "Let's see how long that will last, Build. My name is Night Rogue! We will meet again!"

Night Rogue flies off into the distance until he is gone. Sento is shocked that this person knows who he is.

He looks up at the moon and the stars, wondering if the future that awaits them is a bright one.

* * *

 **A/N: That's it for the Build crew's origin. Now starting next chapter, we'll return to Izuku and the My Hero part of the story. Things are going to go similarly to canon, with only as few differences here and there. Also, the Build crew will show up eventually and the story will really pick up.**

 **Next chapter will see All Might answer Izuku's question and the return of a certain sludge villain.**

 **Prepare for lots of excitement and training, Also many tears, cause Izuku and Inko, you know. Oh, and quirks, lots and lots of quirks.**

 **With that said, Plus Ultra everyone! DarkAbyssBreak out!**


	7. Heroes aren't Born, They're Made

**Another week has come and gone. Sorry for the delay! I was busy with a ton of school-related things and health stuff. DarkAbyssBreak here, back with the next chapter of Be The One For All! The weekend has just started for me and what better way to kick it off than writing more chapters for this story.**

 **I've been rewatching Kamen Rider Build and My Hero Academia to gain some more inspiration for the direction that I want this fanfic to take. I believe that I've got the roadmap set up and that things will be perfect.**

 **This chapter follows up directly after the second chapter, Deku:Origin. All Might will finally answer Izuku's question, the sludge villain will strike again, and a young man will begin walking down the path of the Hero! There may be some differences here when compared to episode 2 of season 1 of the Canon My Hero Academia. Maybe even a bit out of order. However, most of the main events and points will still be present, rest assured!**

 **Now that that's out of the way, let me say this. I do not own Kamen Rider Build, My Hero Academia, or any of the soundtracks mentioned.**

 **Now, here's the highly anticipated chapter, Heroes aren't Born, They're Made.**

* * *

 **Heroes aren't Born, They're Made**

 **Rooftop of a building somewhere in Musutafu, Touto, Japan**

All Might had been caught off guard. This quirkless young man, who seemed to be his biggest fan, had posed him a very difficult question. There was no real way to answer the boy without crushing his dreams. All Might thought to himself: _"No, I am All Might! Surely I can do something for him!"_ He remembered that he was in need of a successor and young Midoriya's question had reminded him of what he himself asked his mentor. He asked the child:

"Young man, what is your name and why do you wish to become a hero?"

Not used to having someone hear out his problems, Izuku answers All Might completely honestly:

"My name is Izuku Midoriya, All Might sir! It's my dream, the one thing I want to do more than anything! You're the number one pro hero and I hope to be somebody as amazing as you! I've always been made fun of and laughed at for being quirkless, but that won't stop me! I want to be there for those in need!"

Just then, All Might deflated in a poof of smoke, revealing a skinny, skeletal looking person in his place. Izuku notices this and shouts:

"What's going on!"

The now weakened All Might explains: "Young Midoriya, what you see before you is how I really look. You know how some guys standing by the poolside puff themselves up to look buffer? It's a lot like that."

Izuku immediately asks: "What happened to you that you now look like this?"

All Might lifts his white shirt on his left side, to reveal a nasty scar with stitching all over it. Izuku puts his hand over his mouth and gasps in shock.

The number one hero tells him: "There was this one major battle a few years back that was kept secret to the public, due to the horrendous nature of the event. The villain who did this to me received quite a few major injuries from yours truly, but the bastard escaped. Thanks to this injury, I can only be a hero for 3 hours a day."

All Might turns to Izuku and tells him: "As per your earlier question, on principle, one shouldn't encourage a quirkless person to pursuit heroics as that would be akin to suicide against a villain with a powerful quirk."

Izuku looked at the floor and wept at All Might's words until:

"However, as a pro hero who is always trying to look out for society and her people, I can't just condemn your dream. Dreams are what make people aspire to be more, to be better, to be PLUS ULTRA!"

Izuku, teary-eyed, looked back up at All Might. He wasn't saying no. He then thought: _"Is he going to say it? My teachers, my classmates, even my own mother didn't tell me."_

All Might told Izuku: "You can become a hero."

That did it. No longer able to hold in his emotions, Izuku openly sobbed and fell to his knees. All Might, the man who he idolized his whole life, just told weak, quirkless Deku that he could be a hero.

All Might walked over to the boy and placed a hand on his shoulder. When Izuku looked at All Might, the hero was giving him the biggest smile that he could muster and a thumbs-up.

All of a sudden, All Might found himself being hugged by the fanboy. Izuku said: "Thank you! No one has ever told me that I could be a hero. You can't imagine what this means to me!"

All Might thought to himself: _"I can imagine more than you know, young Midoriya."_ the hero remembering his own past and origin.

After Izuku released All Might from the hug, the symbol of peace decided to share a few things with the green-haired kid: "For starters kid, you probably already know this, but my name is Toshinori Yagi. You've impressed me with your spirit and determination! Hence, I will personally train you to be a hero! What do you say, young Midoriya?"

Izuku replied: "Yes! I accept!

All of a sudden, the pair on the rooftop heard an explosion. They turned to find the source of the noise and both of them saw a cloud of smoke a few streets down from where they were.

Izuku and All Might both had the same thought: _"What could that be?"_

* * *

 **Half an hour before All Might and Izuku's rooftop talk**

A certain sludge villain was confined to the cola bottle that All Might had trapped him in. He thought: _"Where am I? Oh yeah, that bastard All Might!"_

The monster was then pulled out of his thoughts as Bakugo kicked the bottle that was holding him out of kick launched the bottle at a lamppost, the pressure releasing the cap off the bottle.

As Bakugo and two of his cronies were walking down an alleyway, heading towards the arcade. The one with the stretchy finger quirk asked Bakugo: "Hey, you were beyond pissed at Midoriya today man! Even if he's quirkless, what will other people say if you keep putting him down like that."

Bakugo use his Explosion quirk to blow up the empty soda can in his hand and replies: "It makes me sick, seeing that damn Deku talking about how he'll be a hero, even though he's useless!"

The other boy sneers and says: "Well, let's not think about that anymore. Why don't we go to the arcade for a while?"

The stretchy finger quirk kid adds with a perverse look on his face: "Yeah, then maybe later, we can go pick up some chicks!" making a crude gesture with his stretching digits.

The explosive blonde-haired instantly shut that idea down: "You morons! If we get caught, there goes my chance at getting into UA!"

Just then, a massive blob of green liquid mass starts to grow and the two kids point at it and they warn Bakugo: "Hey, look!"

The blob reveals a set of eyes and a grotesque-looking mouth, it grins and proceeds to proclaim: "How lucky! I managed to find the perfect body suit, young and with a powerful quirk!"

 **Back to Izuku and All Might**

Izuku asks his hero: "All Might! What is happening over there?"

The hero answers: "Most likely, a villain attack."

The boy asks: "How can you be sure?"

All Might points at the scene and says: "Look over there."

Izuku looked at where All Might was pointing to and he saw a giant Mt. Lady making her way over to the area.

All Might, with a heroic look on his skinny face, told the child: "Young Midoriya, let us go to the source for this problem to verify the situation with our own eyes!"

Izuku's eyes shone with eagerness: "You're letting me come along?"

All Might smiles confidently reminds Izuku: "Before, I mentioned that I am going to train you, correct? Well, part of that includes witnessing a villain attack and understanding the scope and magnitude of such a situation. Think of it as your first test!"

Izuku nods his head: "Yes sir! Let's go right now!"

The pair make their way down the flight of stairs, determined to see what the cause of that smoke was.

* * *

 **Tattoin Shopping District**

Civilians were screaming and shouting out for help. The sludge villain had taken control of Bakugo and was using the boy's quirk to cause mayhem and destruction.

Death Arms was at the scene with two of his fellow heroes and a couple of police officers and said: "The monster's taken that kid hostage?" The punching hero charged at the fiend: "You coward!"

As the hero landed a punch onto the blob, he noticed that his fist was merely sinking in and that the creature did not seem fazed at all. He asked: "What's happening here?"

The sludge villain grins maliciously and uses an arm to swat the hero away, causing Death Arms to crash into the front door of one of the district's stores.

As the two heroes who accompanied Death Arms tried to get to him, the villain attacked them as well and told them: "Stay away from me, heroes!"

The evildoer noticed that Bakugo was stubbornly trying to break free, the angry boy shouting: "I'm not gonna let some garbage like you use me for this!"

Bakugo tried using his quirk, but all that did was cause several explosions, which destroyed a lot of the surrounding area.

The sludge villain exclaimed: "This is more than I could've hoped for! With this kid's quirk, I can crush these fools and then go after All Might!" The villain laughed at the thought of defeating the symbol of peace.

The monster grew and surrounded Bakugo with more sludge. The ground began to shake with tremors. Some of the female bystanders pointed out: "There she is! Mt. Lady will stop him!" True to the civilian's word, Mt. Lady was running toward the monster. She paused when she noticed that the space between the buildings was too small and complained: "I need at least two lanes worth of space! I can't get through!"

Meanwhile, Kamui Woods used his wooden branches to rescue the two kids who were hanging around Bakugo earlier as well as two other civilians. He shouted out: "Dealing with explosions isn't my strong suit! Someone else will have to resolve this!"

Backdraft, was occupied with putting out the fires that were produced from the sludge villain using Bakugo's quirk. He thanked Kamui: "I appreciate the help! My hands are full at the moment with these fires! Where's the Fire Department?"

Meanwhile, back with Death Arms, the situation remains unchanged. The sludge villain is still in possession of Bakugo and is using both of their quirks to create havoc all around him. The punching hero dismays: "He's too sticky! We've got to save that boy somehow!"

Bakugo can be seen still trying to fend off the sludge monster that is attempting to take control of his body, but to no avail.

The sludge villain uses one of its limbs to strike at the heroes once more, causing them to jump back for safety.

Death Arms states: "It's useless! There isn't a hero among us right now with a quirk powerful enough to take this guy down!"

One of his fellow heroes says: "We gotta wait until a hero with a suitable quirk can get here!"

Just then, a burst of flame shatters the window of one of the burning buildings in the vicinity. Backdraft, who's still putting out the flames with his water quirk shouts: "I'm held up right now! You'll have to find someone else!"

Kamui Woods, who's using his Arbor quirk to lift civilians onto one of the few buildings that are not ablaze assures: "Don't despair, I'm positive that the right person will show up!" he looks at Bakugo and says: "I feel for the kid, but unfortunately, he'll have to tough things out until the time is right."

Death Arms looks on hopelessly and curses: "Damn it! I wish that I was strong enough to stop that guy this instant!"

* * *

All Might and Izuku arrive to the scene, in the back of the crowd that has gathered to see the commotion, far enough back from prying ears.

One civilian asks: "What's up with the pros not doing anything?"

The man's friend in the crowd answers: "The villain captured a junior high schooler. So the heroes are playing things safe. It's been a while now."

Another person points out: "Hey, wasn't that the sludge villain that All Might was after before?"

Everyone in the crowd pipes up:

"All Might?"

"He's here?"

"He'll save us!"

"But where is he now?"

Izuku points out to All Might: "Hey look, it's the sludge creature! The bottle that you trapped him in must have fallen from your pocket while we were in the air!"

All Might confirms: "Yes, it seems to be the case, young Midoriya."

Izuku clenches his fists and mutters: "It's all my fault."

The skinny man is quick to calm the boy: "This is in no way your fault. The blame lies with me. I overestimated my time limit and wasn't careful with the bottle. I'm pathetic."

Izuku immediately tells Toshinori: "You're the furthest thing from pathetic!" The young man's sudden declaration surprises the number one hero "You've always done your best to save everyone with a smile! You used your remaining time to save me from that very villain!"

Izuku takes another look at the scene and notices the person in the villain's grasp: "That's Kacchan!"

All Might asks: "You know the boy?"

The green-haired hero fan explains: "That's Katsuki Bakugo. We're classmates."

All Might begrudges himself: "If I could have a few more minutes, I could muster up the strength to get in there and save young Bakugo!"

Izuku, hearing his hero's words, looks at Bakugo, then to the crowd of civilians and the pros who were standing idlily by, and then back to All Might's skinny figure. His mind made up, Izuku states to All Might: "I'm going to going distract the villain. In that time, just focus on recovering your power, All Might!"

 **(Kamen Rider Drive OST – Don't Lose Your Mind starts playing)**

The hero hopeful dashed from the crowd like a man possessed. Death Arms shouted at him: "Stupid kid! Come back, it's too dangerous!"

Izuku ignored the pro hero and kept running. He couldn't do anything less. He had only one objective at the moment, keep the villain busy so that All Might could regain his strength.

The green-haired boy thought to himself: _"What I am doing? Normally, I'd be too terrified to even consider doing something like this! Is it because Kacchan's in danger? Was it All Might telling me I could be a hero? That nobody in the crowd is doing anything? I can't say for sure. All I know is I_ _ **WILL**_ _make a difference!"_

Bakugo noticed Izuku running toward him and asked: "Deku?" The sludge villain saw Izuku running towards him and said: "It's body suit #1! I can finally pay you back for earlier! How's about I blast you to smithereens!" The monster raised one of its limbs and formed a hand. It launched the arm at Izuku, the palm of the hand containing one of Bakugo's signature explosions in it.

Izuku quickly assessed: _"The villain is using Kacchan's quirk. With all of this fire surrounding us, Kacchan will be sweating a lot of Nitroglycerin and that means more explosions."_ The boy reached a conclusion _"Wait a minute, if I dodge the explosions and trick the villain into destroying some of the burning structures, the rubble might naturally put the fires out and get All Might the time that he needs."_

With a solid plan in mind, Izuku began to implement his idea: "Hey ugly! Over here! I bet you're one of those D-list villains who talks a big game, but can't back it up!"

The sludge man grew a tick mark on his forehead and was irate: "I'll show you D-list, you're dead kid!" The monster aimed the explosion at Izuku, who tucked and rolled out of the way. The explosion toppled the burning building that Izuku was standing right in front of.

Two minutes had passed and the pro heros and civilains could only look on dumbfounded. This young boy was risking his life to keep the villain's attention and it was working! He was doing what the adult pro heroes couldn't. Everyone was amazed:

"That kid has guts!"

"He's one brave little guy."

"He's keeping the villain distracted! A hero will swoop in and save the day!"

* * *

Izuku was ragged. All of the burning buildings were felled and the fires were gone. He was breathing heavily and running low on stamina. It was taking everything he had just to make the normal movements possible. The sludge villain saw this and shouted: "You're running low on steam, kid!" The evildoer used Bakugo's quirk, hurting the boy in the process, to create an especially large explosion in his right hand, determined to blow up the kid to kingdom come "Say goodbye!"

All Might saw the young men in peril and was driven to push the limit of his recovery time. He gripped his hand over his chest and began to emit smoke. He thought to himself: _"I'm almost done, just another 30 seconds. Don't die on me, young Midoriya, I'll save both you and young Bakugo!"_

Izuku saw the immense blast that was heading his way and thought: " _Think! What can I do? Wait," he remembered his notes on Kamui Woods and his signature move "I got it!"_

Izuku grabbed his backpack from his back and threw it at the villain's face. The impact caused the contents of Izuku's bag to spill out, causing things like sharp pencils, a protractor, and all 13 of the boy's hero notebooks to hit the creature right in the left eye, partially blinding him.

The monster yelled out: "My eye! You little bastard! You'll die for that!"

 **(Music stops playing)**

Using his still good eye to see his victim, the sludge monster was about to use its arm to simply pulverize the boy. Izuku put both of his arms up, in an attempt to defend himself. Death Arms and the other pro heroes tried to get to Midoriya, but were too slow.

 **(My Hero Academia OST – You Say Run starts playing)**

The villain's attack appeared to have hit its intended target, but as the dust cleared, who else but All Might in his muscle form jumped in and intercepted the villain's blow.

Izuku was astonished to see that he was alive. He was sure that he should've died right there. He turns to meet All Might's iconic smile and says: "All Might…"

The symbol of peace tells the boy: "You did well to buy me the time I needed, young Midoriya. You've also lit a new fire in me through your actions. For all of that, you have my thanks!"

All Might then turned to the villain and grabbed Bakugo's arm. He began to spray blood from his mouth and exclaimed: "Pros are always putting their lives on the line, and I am no different!"

The sludge creature spews out hatefully: "All Might!"

All Might winds back his right arm and shouts:

 **DETROIT SMASH!**

The force of All Might's super punch caused the sludge villain to burst and fall apart, freeing Bakugo in the process.

 **(Music stops playing)**

The pro heroes and civilians alike are beyond stunned with All Might's magnificent display of power. All of a sudden, it began to rain. Everybody looked up to see that All Might's punch had changed the weather.

Death Arms gasped and said: "He made… clouds?"

 **(My Hero Academia OST – I Am Here! starts playing)**

All Might, the world's symbol of peace stood proudly with rain showering him from above, in the wake of his victory and raised his right arm with a closed fist up high.

The people lost it. All Might had won again. There were several reactions:

"He changed the weather!"

"He did it!"

"What else did you expect from All Might?"

The crowd erupted into cheers and endlessly praised the hero.

Izuku, still a bit shaken from the experience, caught All Might looking over at him, and gave his idol a thumbs-up. All Might returned the gesture. Bakugo just looked down at the ground, confused but reluctantly grateful that he had been saved.

 **(Music stops playing)**

* * *

 **Izuku is Narrating**

 _After All Might's Victory, the pro heroes and the police rounded up the remaining pieces of the sludge villain and took him away to prison. While All Might was answering questions for the press who had arrived, Kamui Woods and Mt. Lady were scolding me for my reckless behavior during the incident. Kamui Woods told me: "You moron! You're not a pro hero. Don't make a habit of getting in over your head!" Mt. Lady added: "Seriously, you could've died! Don't go making problems for us heroes!" Death Arms notices his fellow heroes being a bit harsh on me and spoke up: "You two are being a little too rough on the kid. Remember, it's because of him that All Might was able to get here in time to save everyone. Today, this boy was a hero!" I felt tears drip from my eyes. First All Might, now Death Arms? I'm doing it! The heroes are noticing my determination!_

 _Kamui and Mt. Lady turned back to me and apologized: "Forgive us, you did a splendid job! Well done!" Mt. Lady said: "Yeah kid, not bad." All Might had finished up with the press interview and signing autographs and came over to where we were. He waved to the pros and said: "Hello there, fellow heroes! I see that you've taken notice of young Midoriya here!" Confused, the heroes asked if he meant me. He nodded eagerly and explained: "Young Izuku Midoriya here is going to be my apprentice. I'm preparing him for the UA entrance exam!" The other pros were shocked. They kept looking at All Might and then back to me repeatedly until Death Arms asked: "All Might, do you know what this young man's quirk is?" Before I could answer them, All Might told them: "Young Midoriya has a strength enhancing quirk, much like yourself and I, Death Arms! He doesn't have much control over it yet, but I saw immense potential in him, as was shown today! I plan to raise him to be a great hero." Mt. Lady asked: "Why didn't he use his quirk then?" Kamui answered her: "Didn't you just hear All Might? The boy has control issues. Also remember, unlicensed civilians can't use their quirks to fight villains. Am I correct, All Might?" The symbol of peace gave out a peace sign and said: "Exactly!" Mt. Lady responded: "Okay, that makes sense now!"_

 _I chose then to ask something of the pros: "Could I please get your autographs for my hero notebook? I'm collecting the signatures of some of the greatest heroes and you three are among them!" Death Arms, Kamui and Mt. Lady were all very flattered by my complements and after hearing that All Might was personally helping me, decided to autograph my notebook. I thanked them immensely and wished them well on their hero careers, and for the lives they've kept safe up til now._

 _Kacchan was off to the side, recovering from the villain attack. He was looking at me very strangely. He likely heard what All Might had said and could have been jealous. I mean, Kacchan was never jealous of me. To him, I was just useless old Deku. That's why I found it strange that when I looked over and waved at him, he didn't curse me out or get riled up._

 **Izuku stops Narrating**

After the crazy day that we had been through, All Might offered to walk Izuku home. He explained that after the sludge villain had attacked the boy before, it would be safer if he kept him company until he got home. They spoke at length about many things. Just before the two had reached Izuku's apartment, Kacchan shouted at us: "Hey Deku!" Izuku and All Might turned out and saw Bakugo standing across from them on the sidewalk. The angry blond-haired boy shouted: "Don't think that just because you and All Might helped me, that I'm helpless! You better get into UA, so that I can kick your ass!" Bakugo then addressed All Might: "As for you All Might, I'll become the number one hero someday. So just keep that spot warm for me until I take over for you!" He left the duo with this: "Later." Bakugo shoved his hands into his pants pockets and shuffled off.

After Bakugo left, All Might deflated back into his skinny self. As the pair almost reached Izuku's apartment, All Might had one last piece of business that he needed to bring up to the boy: "Young Midoriya, you have proved yourself today as possessing the qualities of a hero, even though you are quirkless. That is why just as my master did for me, I would like to have you be the one who inherits my quirk." Izuku's eyes bulged and he rapidly asked: "Wait, All Might, you can pass on your quirk?" At this, Toshinori Yagi grins and opens the palm of his right hand. An image of a bright light appears in All Might's hand as he explains his quirk to Izuku: "The name of my quirk is One For All. As the name implies, this one power exists for the benefit of the many. The power is passed on from user to user, cultivating the power and strengthening it with each generation. I was actually searching for a successor, and now that search is over. I've found you, young Midoriya! So, will you accept my power and become my successor?"

Izuku did not hesitate to tell his hero: "I'll do it, All Might!"

All Might was overjoyed: "Do not worry, young Midoriya! I'll help prepare you to inherit my power as well as get you ready for the UA entrance exam!"

Izuku bowed his head in respect and reverence to his hero and simply said: "Thank you, All Might!"

Izuku had bid All Might farewell. They exchanged their contact info to begin Izuku's training the next day.

After Izuku entered his apartment, Toshinori Yagi pulled out his cell phone and called principal Nezu. The head of UA answered the phone and asked: "All Might? To what do I owe the pleasure of you calling me?"

All Might buffed up for a few moments and in an excited tone of voice, told Nezu: "Sir, I've found my successor!"

* * *

 **A/N: And there's yet another chapter done. The next chapter will feature Deku's training montage, All Might's unique training methods, Izuku's fortitude, and encounters with a few certain other hero hopefuls that most of you are likely familiar with.**

 **I apologize for the delay in the chapter! Life just has this nasty habit of getting in the way. I'll try to update as frequently as I can. The periods in between chapters definitely gives me time to think of how I want the next chapter to go.**

 **Also, since I'm focusing on the My Hero Academia side of this fanfic at present, I wouldn't expect to see the Build crew again until sometime after Izuku joins class 1-A. I'm looking forward to writing up character interactions between class 1-A as they're a colorful cast of characters.**

 **Have a great weekend viewers, Plus Ultra! DarkAbyssBreak out!**


	8. The First Step to Shaping One's Vessel

**Hello everyone! DarkAbyssBreak back with the next chapter! I've been busy playing Pokemon Let's Go Eevee and have only now stopped playing long enough to roll out a new chapter. As a form of apology, I thought that I'd make this chapter a big one, and begin on the next one as soon as possible.**

 **This chapter will see All Might train up Izuku in order to inherit One For All. Lots of muscles, sweat, pain, tears and progress will be present! As the number one hero begins to train his successor, more of Izuku's daily life will be revealed. Also, the other UA applicants will show what they can do in order to reach the top. Mainly, Bakugo, a round-faced brunette, and a glasses-wearing rule follower will appear during the exam.**

 **I do not own Kamen Rider Build, My Hero Academia, or any of the soundtracks mentioned.**

 **Now, here is the chapter!**

* * *

 **The First Step to Shaping One's Vessel**

 **Dagobah Municipal Beach Park, One day later, 7:00 AM**

Izuku was struggling to pull a huge refrigerator using some rope. It wasn't helping that All Might, in his muscle form, was sitting with his butt planted firmly on the appliance. The green-haired kid asked the hero "Hey All Might, why am I lugging around junk?"

The symbol of peace answered "It's because you're not yet a perfect vessel!"

Izuku stopped pulling the rope and asked "What do you mean by that?"

All Might elaborated: "While you do have the type of character that I was searching for in a successor, your body is another story. If a weak body were to inherit One For All," an image of Izuku's limbs being blown off of his body can be seen "it would not be able to properly contain the power and the person's limbs would pop right off!"

Izuku recoils momentarily, but after composing himself, realizes "So we're here to build up my body so that I can be a strong enough vessel!"

All Might smiles widely and says "Exactly! I knew that you would understand!"

The hero added "However, seeing as the UA entrance exam is in 10 months time…"

Izuku cuts him off and says "That means I only have those 10 months to develop my body and receive your quirk."

The young man proceeds to ask "How come you chose this place to do our training at, All Might?"

Toshinori tells him: "I heard that this part of the beach was filled to the brim with junk that people simply left here for years and no one has done anything about it." All Might slams his fist down and clears part of the huge junk pile, revealing the sun and the segment of ocean behind it. "You will clean up this whole section and return the beautiful view to the beach and her people!"

He also states: "This will be your first step towards the world of heroes!"

An overwhelmed Izuku lets out: "My first step."

All Might pulls out a stack of papers and says: "To achieve that, I've written up what I believe to be the best training regimen for you. I call it the "Aim to Pass: American Dream Plan"! You will have to apply every part of this part to your life for the whole time we are training!"

Izuku sorts through the plan and comments "Wow, this is very thorough and well-organized, even sleep time is included!"

All Might leans into Izuku's right ear and asks the boy "To be blunt, this will be a gruesome track. Knowing this, do you still want to continue?"

Without hesitation, Izuku tells him "No problem, I've been behind for my entire life. Compared to what I've been through til now, this is nothing!"

* * *

 **(My Hero Academia OST – Battle of Deku begins playing)**

 _And so began my dreaded ten months of hell._

Izuku was pushing a file cabinet with All Might telling him to push it over to the truck. He is then shown to be running while carrying a tire over his shoulder with All Might motivating him.

Izuku starts mumbling in the middle of class, freaking out all of his classmates as well as his teacher, who calls him out on be distracted. This leads to the rest of the class to laugh at him and Izuku blushes a bright red, sinking into his desk out of embarrassment.

He's shown to be pushing a much larger tire, only it is sideways and flat on the ground. All Might is giving him tips on how to more easily moving the object, despite the lack of strength the young man is currently working with.

Izuku is seen at home, showing his mom his training plan and explaining that he needs to change up his diet to compensate and to help build muscle.

He can be seen chowing down on some pasta, salad and rice for dinner in order to carbo-load for the training. Come morning, Izuku has his face in the books, studying extra to not fall behind in school.

A few hours later, he meets back up with All Might at the beach again and starts trying to push a very large safe. He then attempted to bench-press more weight than his body could safely handle, and All Might bulked up to helped him from being crushed.

That same day when Izuku had gone home, he was doing 100 push-ups after dinner in order to burn off some extra calories and build more muscle. This was extra work that the green-haired boy was doing separately from All Might's plan.

At school, Izuku was almost dozing off in the middle of class. His tenacity towards reaching his goal was the only thing keeping him from missing the class lecture. Back at home, Izuku was scarfing down the dinner that his mom had made, with Inko Midoriya only able to blankly stare at Izuku putting away all of the food he was consuming.

Izuku worked off his dinner by going for a jog at night.

The next day, Izuku was feeling very nauseous from the amount of physical activity that he was doing and he leaned over a barrel and puked. All Might simply shook his head at his trainee and let Izuku get everything out of his system.

Izuku was swimming laps in the beach's ocean with All Might overseeing his progress. Some female beach-goers took notice of All Might and they approached him to feel his muscles and admire him. The number one hero decided to humor them, so that they wouldn't notice that he was training Izuku.

Izuku was lifting some dumbbells at home. Back at the beach, Izuku managed to get quite a few appliances and junk out of the pile. All Might had Izuku carry him and walk in order to get the boy used to carrying heavy loads.

All Might, in his skinny appearance, was riding on a Segway in front of Izuku, who was carrying a small safe while running when the boy suddenly began to feel heavily fatigued. He fell over, dropping the safe. All Might hear the noise and stopped to turn around "You won't make it into UA like that! You only have 3 months left, young Midoriya!"

The hero then saw how rigidly Izuku was moving when he tried to get up and thought _"The kid's been overworking himself!"_ All Might asked Izuku "You haven't been sticking to the plan, have you?" Izuku tells him "Sorry, All Might. I have to work past my limits, or else I'll never become my ideal hero! I'll want to be the kind of hero that you are!"

The boy's words resonated with Toshinori and the blond hero responded "Well if that's how you feel, then let me adjust the plan for you! We'll get you into UA and you will be a hero, young man! Hahahahaha!"

 **(Music stops playing)**

* * *

 **Day of the Entrance Exam, February 26, 6:00 AM**

All Might had stepped out of his trunk and was at the beach to check on how Izuku was doing. Out of nowhere, he could hear the boy shouting at the top of his lungs atop a singular pile of junk. All Might went wide-eyed. The beach had been restored to its former glory. "He even cleaned outside of where I told him to. He really did a 110% perfect job!" All Might shook for a bit "Oh my… Oh my..." He then turned on his muscle form and grinned "goodness!"

Izuku fell from the junk pile and All Might swiftly zoomed over and caught him. The hero put him down and told the boy "Nice work. You teenagers sure are something, huh?" He then pulled out his cell phone and showed Izuku a photo of him from 10 months ago. Looking at Izuku now, the difference was like night and day. Izuku now had very well-developed muscles. His arms, legs, shoulders, biceps, back, pecs, and abs were solid and deserving of one who wants to be the best.

All Might held out his arms in a grandiose fashion, the sun shining in the background and continued "You have just barely met the physique to inherit my quirk! Congratulations!" Izuku's eyes watered and he told his hero "I'm too blessed. You helped me reach this point. I'll always remember this, All Might!" To that, All Might thought _"You worked your butt off, young Midoriya. Even some pros wouldn't be willing to invest the time and effort that you have and I am proud of your resolve!"_

All Might pulled out a strand of hair off of his head and held it out to the confused boy. The hero explained "Please keep this secret, young Midoriya. This is how One For All is transferred from person to person. You need only two things now to receive my power. The first is my approval. One For All cannot be forcibly taken away and you need for me to allow you to gain it. The second is that you need to take in my DNA in some form, a hair should suffice. Now, are you ready?"

Izuku said "Of course, sir!" The green-haired young man reached out and grabbed the hair from All Might and swallowed it. Toshinori further explained "As your stomach acids break out and digest my hair, you should inherit my quirk in about 2-3 hours. Keep in mind that you just took on One For All, so don't expect complete control over it." Izuku was taking in all of the information from the man he respected more than anyone. "To fire off my power, clench your butt cheeks and yell from the bottom of your heart!" All Might turned to face the ocean and punched.

 **SMASH!**

The air pressure from All Might's punch split the ocean for a few seconds before returning to normal. The hero turned to Midoriya and said "Just like that!" Izuku was awestruck at All Might's strength and the fact that he too will have that power.

* * *

 **UA High School, Entrance Exam Location, 8:40 AM**

Izuku, wearing his black school uniform and yellow backpack, had approached the entrance of UA's test site. As he began walking towards the building amongst the other applicants, someone behind him shouted "Outta my way, Deku!" Katsuki Bakugo had shown up and true to form, told Izuku "Don't mess with me, or you're dead!" Izuku sighed and told him "Good luck, Kacchan." Bakugo stopped right in front of him, no expression on his face. He told Izuku "Don't fail the exam like most of these extras will. If you could save me, who knows? Maybe you'll pass." Bakugo made his way inside the building.

Izuku wasn't expecting those words from Bakugo. Just as Izuku reached the gate and took his first step forward, he tripped over the step and started to fall. He closed his eyes and just as he expected to hit the ground, he didn't. He opened his eyes to see that he was floating. He heard a girl ask "Hey, are you doing okay?" He looked up to see a brown-haired girl with gravity-defying hair. She had blushes on her cheeks and was wearing a brown coat, a pink scarf and a black backpack.

The girl set Izuku down firmly on the ground, and tapped her fingertips together. She said "I'm sorry! I used my quirk to keep you from tripping. I'm sure that's better than you messing up your face on the floor!" The nice girl took out her right hand and introduced herself "I'm Ochako Uraraka! And you are Deku, right?" Izuku asked "How did you know that?" Ochako looked a bit sheepish "I heard that loud blonde boy call you Deku, so I figured that it must be your name!" Izuku told her "Deku is what he calls me, kind of a nickname, but you can call me Deku if you want!" Izuku smiled, shaking the hand of the girl who helped him and said "My name is Izuku Midoriya! Thank you, miss Uraraka!"

The girl got quite flustered and the blushes on her face became more pronounced as her head began to resemble a tomato. She quickly composed herself and before leaving, she told Izuku "Good luck on the exam!"

After that, Izuku made his way into the UA building.

* * *

 **UA Exam Orientation Room**

All of the examinees were seated in the large room. They were all anxious about the exam, so most of them were quietly gathering their thoughts and trying not to lose their minds.

Present Mic was at the podium, giving his introduction to the students. "Hey there, all you listeners taking the entrance exam! Welcome to today's show! Everybody say "Hey!" No one responded to Mic either out of nervousness or awkwardness.

Present Mic shrugged and said "That's certainly one way to go." He then proceeded to get right down to business. "Let me drop what your practical exam is gonna look like!" As Mic was setting up the screen for the exam visuals, Izuku was freaking out over the hero being in charge of their group "Holy crap! It's really Present Mic! I listen to his radio show every day! So cool!" The young man had sparkles in his eyes and those around him were giggling at the fanboy's eccentric behavior.

Bakugo, who was sitting right next to Izuku, calmly told him "Hey Deku, pipe down so the rest of us can hear what Mic is saying." Izuku stopped his rambling and rubbed the back of his neck and said "Sorry."

Present Mic continued his explanation "After I'm through going over some things here, you guys and girls will all be engaging in 10-minute battles." The screen behind Mic showed the orientation room and the 7 battle centers labeled A through G. "You can bring whatever you want! Once we've wrapped things up here, you are to head to the specific center list on your examinee cards, okay?!"

Izuku and Bakugo looked at their cards and noticed that their test centers were different as Bakugo's was A and Izuku had B. Bakugo openly stated "So, they thought to keep us from taking our exams with people we know. That's pretty smart." Izuku added "Yeah, I imagine that if for example, you and I were to be at the same test center, we could combine your brawn with my smarts and the other candidates would be hard-pressed to stop us." Bakugo didn't argue with Izuku's point. Instead he said "You lucked out, us being in different testing centers means you have a better chance at passing."

The screen changed to display an image of an urban setting with a model made of buildings. 3 different enemy types with the values 1P, 2P, and 3P showed up. Present Mic elaborated "There will be 3 different types of fake villains in each battle center. They are worth 1, 2 and 3 points respectively. The goal is for you all to stop these fake villains using your quirks in order to rack up them points. Naturally speaking, going after your fellow test-takers and any unheroic acts are not allowed!"

A taller fellow with black hair and glasses stood up with his hand raised up high and asked "May I ask a question?" Mic said "What's up?" The examinee held out a printout and pointed to it "On this printout, there seems to be a fourth type of enemy listed. If this is a mistake, then it is quite shameful for UA, the most prodigious hero school in Japan!"

Present Mic waved his hands in a placating motion "Okay Examinee number 7111. Thanks for catching that. The 4th type of villain isn't worth any points, it's basically just there to cause problems for you, the ones participating in the exams! It will appear in narrow spaces and it is highly recommended that you all avoid it." Examinee 7111 then excused himself "Thank you very much, please continue!"

Two of the examinees in the crowd were talking about this new development "It's like an obstacle that you'd stay away from in a video game, huh?" The other boy added "This whole test feels like a game."

Present Mic concluded the presentation "That's all that I've got for you kiddos. I give you all a special surprise, our school motto! Go Beyond. Plus Ultra!" Izuku looked on with determination.

* * *

 **UA High School Hero Course, Entrance Exam, Battle Center B**

Izuku and his fellow examinees were standing outside of the gate, awaiting the exam to begin. He thought to himself _"I can do this._ _Those months that I spent with All Might prepared me for this. I'll become a hero!"_

Izuku then noticed the girl who kept him from falling earlier that day _"It's her! The nice girl! I believe her name was Ochako Uraraka. I should go over there and thank her for helping me!"_

Just as Izuku was about to make his way over to Ochako, the tall lad from earlier approached Izuku and placed his hand on Izuku's right shoulder. He asked Midoriya "Hey you! Can't you see the girl over there is trying to focus? Are you here to disrupt the other examinees?" Izuku quickly responded "No, I'm not! You see, that girl over there, she kept me from falling earlier today at the front gate with her gravity quirk and I just wanted to thank her."

The taller boy looked embarrassed and promptly apologized "I see. You know her from before. I'm so sorry, let me introduce myself," The boy offered his right hand for a handshake "My name is Tenya Iida." Izuku smiled and shook his hand "I'm Izuku Midoriya." Iida then said "Well, how about I accompany you to greet our fellow examinee?" Izuku told him "Sure, why not?"

The pair made their way over to Ochako, who was taking deep breaths and trying to stay motivated for the exam that would begin any moment now, when she noticed the green-haired boy from before, as well as the tall boy with the glasses who asked Present Mic about the fake villains. Izuku waved over to her as the two approached her. Curious as to why they were here, she said "Oh Deku-kun, good to see you again! Looks like we're in the same battle center!"

Izuku answered "Yeah, seems that way. I wanted to thank you again for helping me before, I really appreciate it Uraraka-san." Iida spoke up "Hello there, Uraraka-kun, my name is Tenya Iida. I had assumed that Midoriya-kun here was trying to mess with you, but it turns out that he was trying to give you his thanks. I merely wanted to apologize to you both." Ochako smiled brightly and told them "Aw, that's so sweet, you guys. Thank you both so much!"

Izuku chose to speak up "Actually, there was another reason why I wanted to talk to you, Uraraka-san. If both of you wouldn't mind, do you want to team up during the exam?" Iida pondered this "You are requesting that the 3 of us join forces, Midoriya-kun?" Izuku told them "Yeah, everybody is probably going to be looking out for themselves during the test and keeping all of the points to themselves. If we work together, the chances of us passing the practical exam are much better than if we were to do it alone. What do you say?" Ochako adopted a serious, pensive look on her face, then she gave the two boys a shining smile and said "Okay, I'm in! You two seem friendly enough and this looks like the best way to pass!"

Iida gave his answer "Midoriya-kun, Uraraka-kun, let us cooperate so that we may attend UA and become heroes!" Izuku was more than pleased that these two were on board with his plan "Don't worry you guys, I'll make sure that all 3 of us get in!"

The 3 students began to discuss the logistics of their plan. They told each other what their quirks were. Ochako said "My quirk is Zero Gravity, it lets me make objects and other people incredibly light to where they're virtually weightless. My limit is about 1 ton and the longer and the more I use my quirk, the more nauseous I become."

Iida shared details about his quirk "My quirk is named Engine. I have engines in my calves that allow me to run at high speeds. I can kick with increased strength and speed. My one drawback is that I must consume plenty of liquids in order to fuel my quirk." Iida then pulls out and shows the two his sports bottle filled with juice "In my case, the fuel is orange juice!"

Izuku told his new friends "My quirk is Superpower, it's a strength-enhancing quirk. It has some pretty strong knockback, so I have to use it sparingly. I basically have the physical strength of several people and if I use repeatedly, I'll be too hurt and worn out. I haven't mastered it yet, but someday when I do, it won't hurt me anymore."

Iida brought something that was on his mind "Midoriya-kun, earlier you mentioned that you'd ensure that the 3 of us pass. Am I to assume that you have a plan ready?"

Ochako chimed in "Yeah! What's the plan?"

Izuku began to inform them about his strategy.

* * *

 **UA High School Hero Course, Entrance Exam, Battle Center A**

Bakugo had made quick work of the faux villains that he faced off with. He was holding the head of a barely functioning robot as his hand started to emit smoke and blew up the machine with an explosion. He was now currently at 50 villain points and by the look of things, he would gain some more. A few more 1 and 2 pointers were headed for him as they designated the explosive hothead as high priority. Bakugo was thrilled at being free to use his quirk against these robots and shouted "All right! I haven't been able to cut this loose in a while! Time to blow some more of these guys away!" Completely focused, the young man ignited his quirk in his palms to launch himself forward and charged at the robots before him.

The other examinees were blown away by Bakugo, and not just due to his quirk. The sheer raw talent and power the guy was exhibiting made some of the students feel inadequate. Some of them hadn't even gotten a single point yet and had thrown in the towel. Others turned to look for robots that didn't have the misfortune of being scrapped by the Explosion user.

At the spectator's booth, Principal Nezu, All Might, and some of the other pro heroes were watching all of the Battle Centers on 7 different screens. Nezu spoke up about Center A's progress "Oh my, the blonde one, Katsuki Bakugo. He's already gotten 50 villain points and disposed of several of the robots, yet he doesn't have a single hero point. One must be able and willing to help others, don't you agree, All Might?"

The One For All user answered his fellow hero with his trademark grin "But of course, Nezu sir! Being a hero is far more than just defeating villains and saving civilians, it's also about helping others and doing what you can to create a better society!"

Toshinori added "With that said, the boy has incredible potential and prowess. I'd say he's already passed the test and we can expect to see him at UA this year!" The number one hero then turned his gaze to Center B's screen and notice his protegee. He thought to himself _"Young Midoriya, I trained you the best that I could during those 10 months. You've worked so hard to get to this point. I know that you'll make me proud!"_

As the other pros were occupied with seeing the potential new students and what quirks they had as well as their strength, Nezu noticed All Might lingering on Battle Center B's screen and remembered _"Ah yes, if memory serves, and my memory is among the finest, that site is where All Might's successor was assigned. One Mr. Izuku Midoriya, if I'm not mistaken."_ The mouse-bear person looked at the green haired boy making plans with two other students. He smiled and thought _"Yes, you chose a fine one indeed."_

* * *

 **UA High School Hero Course, Entrance Exam, Battle Center B**

With their plan ready to go, Izuku, Ochako and Iida joined their fellow examinees at the Battle Center's front gate. Present Mic put his hands on his sides and shouted "Ok everybody! Exam Start!"

 **(Under Night In-Birth OST - Scraper Sky High(Hyde's Theme) starts playing)**

Without hesitation, all of the applicants were off to the races, looking for robots to destroy. Izuku's group had begun to implement their plan. Iida using his Engine quirk, sped ahead of everyone and found some of the first robots. He waved his hands, signaling to his friends "Midoriya-kun! Uraraka-kun! I have found some!"

Izuku turned to Ochako and told her "Alright, now Uraraka-san!" The young girl responded "Ok Deku-kun!" Ochako had touched her padded fingertips together, activating her quirk. She moved to touch both herself and Izuku to make their clothes lighter so that they would become a bit faster. It worked as Izuku and Ochako were outpacing the others and reached Iida. They stood in front of three 1 pointer robots and they each took one down. Iida swiftly kicked his in the back, exposing some wiring and downing the mech. Ochako used her quirk to make hers float, then released Zero Gravity which caused the villain to fall to pieces upon hitting the pavement. Izuku dealt with his by sliding beneath it and pushing the deactivation button hidden on its back, causing it to shut down.

Iida complemented his new pal "Very good, Midoriya-kun! How astute of you to shut down the robot!" Ochako tilted her head and asked "How come you didn't use your quirk? Izuku blushed at how cute Ochako looked and hastily replied "It's because I'm saving my quirk in case something dangerous shows up, like a stronger villain, so I can let my quirk loose on it." Iida nodded at the logic and said "So be it. We'll respect your choice and if we run into something more troubling, we'll look to you for assistance." Ochako nodded at this and gave Izuku a thumbs up "Yeah Deku-kun, no problem!"

 **(Music stops playing)**

Quite some time had passed and Battle Center B's exam was ¾ done. Izuku, Iida and Ochako had managed to rack up 15 points each after dealing with a mess of the fake villains that challenged them. However, they still needed some points if they wanted to pass the exam. Just then, a massive rumble could be felt by everyone in the area.

Izuku asked out loud "What the heck is that!?" Ochako had a hand over her mouth, trying to handle her nausea from using her quirk a lot "Oh man! First all of those robots, now this shaking! My poor tummy can't take much more of this!" Iida pointed his finger at something and yelled "Look over there!"

The trio, as well as the remaining participants saw the fabled 0 pointer faux villain. This was a robot of a completely different class than the previous ones. It looked army grade in quality and was enormous. All of the other examinees turned about and started to run away. Izuku and his friends were about to do the same when all of a sudden, the massive robot picked up one of the fake buildings off of the ground and proceeded to throw it at the fleeing students.

Back at the spectator's booth, All Might was watching the end of Battle Center B's exam with anticipation _"Come on, young man! Now is the time to use One For All. This is what the power is meant for!"_

* * *

 **(My Hero Academia OST - You Say Run starts playing)**

Izuku tells Ochako and Iida "We gotta stop that building from hitting the others!" Iida immediately says "That's too much, we're not pros yet!" Izuku tells them both "With the three of us, we can do it." Ochako tells Izuku "Deku-kun, I can probably use my quirk just one more time today, cause I'm also barfing over here. But I'll help!"

Izuku explains "Uraraka-san, use Zero Gravity to make me as light as you can, while Iida-kun, you throw me while you run and I'll use my quirk to smash the building to pieces." Iida decided to trust them "Okay, let's do this!"

Ochako used her quirk once more to lighten Izuku, then she started to puke immediately after. Izuku told her "I'm sorry, Uraraka-san! Thank you!" She steadied herself and told them "Go save them, you two!" Iida then grabbed Izuku and began to run using Engine. As soon as he was close enough to the falling building, Iida threw Izuku "Here you are, Midoriya-kun!"

As Izuku was sailing through the air towards the building, he reached deep inside of himself and remembered how All Might used One For All. " _I just have to tell myself that I can do this. I WILL DO THIS!"_ He pulled back his right arm for a punch and red veins of energy started to form around his body from his feet all the way up to his arm. He aimed for the large object in the air and shouted

 **SMASH!**

The pressure that was released from Izuku's attack completely destroyed the fake building that the 0 pointer threw, turning it into rubble and saving the other students. Just as Izuku was taking in the first time that he had used his quirk, he noticed that he was falling really fast and that his right arm was bruised and broken from the smash. _"Oh no! That was 100% right off the bat! Of course I'm not used to it yet, but I had to save them."_

 **(Music stops playing)**

Before Izuku hit the pavement, he was caught by Iida and Ochako. They hugged him and checked to make sure that he was okay. Iida said "Midoriya-kun, what you did was nothing short of heroic!" he was gesturing with his hands as though he were a robot "Your plan succeeded!" Ochako gave her two cents on the matter as well "Deku-kun, you really did it!" Izuku looked at his friends and with a smile, told them "No you guys, we did it."

Recovery girl walked up to the 3 and saw Izuku's battered arm. She rebuked "Look at what you've done to yourself kiddo, you look like a huge mess! Well, no worries, that's why I'm here." Everyone around was confused as to who the old nurse was, as a blond haired French looking boy said "That's the pro hero Recovery Girl! She can heal people with her quirk, she's the reason why UA can conduct their exams so roughly, oui!"

Present Mic shouted "That's time! The practical exam is now over! You'll all receive your results and whether you passed or failed in about a week's time! Until next time viewers, yeah!"

All Might was beside himself. Not only had he found a worthy successor in Izuku Midoriya, the boy had shown that he works well with others and is intelligent beyond his years. He said to himself while watching Izuku talk to his friends "Young man, I will ensure that you become an amazing hero, this I swear!"

After the exam was over and Izuku's arm had finished being healed by Recovery Girl, Izuku, Ochako and Iida were waiting by a bus stop to get a ride home. Iida proposed "Say, why don't the 3 of us exchange phone numbers? We worked quite well together and I'll admit, the two of you have started to grow on me." Ochako pulled out her cell phone and responded "Sure! We can text and chat and keep in touch with each other!" Izuku nodded and agreed "Yeah, why not?"

After the 3 friends shared their contact info with each other, they said goodbye as they each took a bus home, eager to hear back from UA about if they passed or not.

* * *

 **One week later**

Izuku was in his living room, doing some bicep curls and maintaining his exercise routine so as to keep his body in shape. He was getting anxious about his exam results and was doing any and everything that he could in order to keep himself busy. Suddenly, his mother comes through the door, on her knees in shock and grasping a letter with the UA emblem stamped on it "Izuku, it's here!"

Izuku took the letter from his mom and went into his room. He opened the letter to find some kind of circular recording device. He set it down on his desk and it displayed a video of All Might. The hero exclaimed "Hello there, young Midoriya! Fancy seeing you again! I bet your wondering why I'm appearing in this recording! Well, I'm going to UA as well, only as a teacher! I figured that it was about time that I passed on my wealth of knowledge and experience as a hero to the next generation of heroes!"

Izuku continued to watch the recording "Now under normal circumstances, yourself, young Uraraka and Iida wouldn't have pass the exam with merely 15 villain points each. However, we also award rescue points and they are given out by a select group of six judges who can each award a maximum of 10 rescue points. I am pleased to inform you that the 3 of you tied for the second highest score on the exam with 15 villain points and 60 rescue points, totaling 75 points. More than enough to attend UA. You three earned these points through your selfless and courageous action you demonstrated last week, and I would be honored to educate you in all manner of herodom."

All Might reached out his hand and said "Come young Midoriya, this is your Hero Academia."

Izuku smiled through tears that he hadn't even noticed were trailing down his cheeks. He was so happy and excited to be going to his dream school "Thanks to All Might, my new friends and surprisingly enough, myself, I go down the path to becoming an amazing hero!"

* * *

 **A/N: So there we have it. Izuku has just been admitted to UA High School, as well as Bakugo, Ochako and Iida too. Next chapter will see Izuku set off on his first day at UA. The rest of class 1-A will finally debut and we may even see the Build crew and what they've been up to since we last saw them.**

 **I will try to get the next chapter done in no later than a week. Sorry for the massive delay. College is taxing and with Finals coming up in 2 weeks, it's a race to get everything done for the holidays. Anyhow, this is DarkAbyssBreak signing off, hope to be back real soon.**


	9. Proving One's Worth

**Hey everyone, guess who's back with the next chapter! Sorry that I'm late, I was busy with Christmas and New Years, like I'm sure the rest of you were as well! I finally found some time to just sit down and write. I've found that this story has been a great way of relieving stress and I'm committed to seeing this through. As a form of apology, I'm making this a big chapter. This chapter of Be The One For All sees Izuku begin his very first day as a first-year student at UA High.**

 **We get to see class 1-A and how they interact with Izuku and each other. A certain erasure hero will also show his scruffy self and the first day of school will be quite the challenge. He'll test their mettle and see exactly what these potential heroes are really made of. Also, just to clarify. Since everyone else dropped out during Sento, Banjo and Misora's exam, those 3, along with Kasumi, are the only students of class 2-A, which is taught by Power Loader. As mentioned in chapter 4, Kasumi applied for the support course, but she's in class 2-A due to reasons.**

 **The Build crew have been attending UA for a year as of this point, and some of their exploits may come up in this chapter. Meanwhile, the villains are building their forces in the darkness of society. The League of Villains are amassing their forces via quirk science and recruiting criminals to their cause. Similarly, Faust is hard at work, increasing the number of Smash in their possession and progressing with their Nebula Gas experiments. An encounter between these two organizations will spell the beginning of disaster for our young heroes.**

 **I do not own Kamen Rider Build, My Hero Academia, or any of the soundtracks mentioned.**

 **Let's get to the chapter!**

* * *

 **Proving One's Worth**

 **Dagobah Municipal Beach Park, 8:00 PM**

After Izuku had received the good news about his acceptance into UA High, All Might contacted him. He said that he wanted to talk at the beach where they trained together. As Izuku approached the location's parking lot, he noticed the number one hero in his skinny form, waiting for him. Izuku waved to his mentor, shouting "All Might!"

A couple who were out on the pier asked "All Might?"

"Where is he?"

Toshinori told Izuku to say that he was mistaken.

He did so "I was mistaken, sorry!"

The couple were disappointed and went back to their business.

All Might pulled out his right hand for a handshake and told his protegee "Congratulations on passing, young Midoriya!" Izuku shook his hero's hand firmly and said "Thank you, sir!"

All Might told him "I didn't inform anyone but Principal Nezu about our relationship to one another, and he told me that you were judged just as fairly as the other examinees. I figured that I'd tell you as you seem to be the type of person who'd be upset that they got in due to playing favorites, am I right?"

Izuku nodded and thanked him for his discretion "I appreciate that, All Might!"

Toshinori grinned and said "No problem!" The hero then added "Also, we were very impressed that you managed to convince young Iida and Uraraka to work with you during the entrance exam, teamwork is essential if you want to be a pro!" Izuku told his mentor "Yeah, those two were amazing, I actually exchanged phone numbers with them and we've been in contact with each other ever since."

Toshinori smiled "So you've befriended them! That's wonderful. They seem like fine young people and I cannot wait to be teaching them as well at UA."

Izuku suddenly remembered "That's right, on the video, you mentioned that you're going to be teaching at UA!" All Might replied "Yes, young man! I'll likely be teaching you as well, but fear not! I'll treat all of my students equally and shape you all into amazing heroes!"

Without notice, All Might buffed up into his muscle form and stood heroically. The couple from earlier saw All Might and the man shouted "Hey, it's really All Might this time! Can we have your autograph?" Toshinori, ever the serviceable hero, responded "But of course, citizens! I'll be happy to do that!"

As the couple thanked All Might again for giving them autographs, Izuku watched on in amazement. Someday, it would be him signing autographs for his fans. With All Might's help, he was confident that he would get there.

* * *

 **Izuku's Apartment, April, 8:20 AM**

After meeting with All Might, Izuku went home and had a good night's sleep. He woke and got ready for his first day at UA. Izuku scarfed down the breakfast his mother made him, eggs, toast and bacon with some orange juice and some coffee. As Izuku was sitting on the steps in front of the front door, tying his shoes, his mother Inko asked him "Izuku dear, do you have everything you need? Food? Money? Bandages?" Inko continued to ramble off several things that she felt Izuku would need to bring along to his first day at UA, but Izuku smiled at her saying "Yes mom, I've got everything!"

Just as Izuku, sporting the UA high school uniform that he was given, was about to head out, his mom stopped him "Honey, I just have to tell you something!" She tearfully told Izuku "I know that when we came back from the quirk specialist that day, that you were crushed that you apparently didn't have a quirk. Turns out you were a late bloomer!" Inko then hugged Izuku and said "I only told you that I was sorry afterwards because if you were quirkless, I didn't want you to be in danger, you know that you're my world, right Izuku?"

Izuku told her "Of course mom! I love you too! Don't worry, I didn't take what you said that day too badly. I know you just want to keep me safe!" After the mother and son broke their hug, Izuku grabbed his yellow backpack and grabbed the door knob, opening the door to leave "I'm heading out now!"

 **(Shokugeki no Soma OST – Morning Field Harvest starts playing)**

As this was Izuku's first day attending UA, he decided to walk there so that he could familiarize himself with the area. Eventually, he reached UA's front gate and walked right inside. It was now 8:50 AM, he had 10 minutes before class started and he was looking for the class 1-A room. He said out loud "Class 1-A, where is the homeroom?" Just as he was speaking his thoughts, he accidently bumped into someone while he wasn't looking. Izuku fell on his butt, while the person he bumped into was still standing.

 **(Music stops playing)**

 **(Persona 4 OST – Like a Dream Come True starts playing)**

The boy who Izuku toppled into asked "Hey, are you alright?" Izuku looked up at the person and noticed that he was very familiar. He then remembered the strange boy that he met before being attacked by the sludge villain that day. He pointed at him and said "It's you! From the other day, we bumped into each other before!" Sento Kiryu then snapped his fingers and said "Oh yes! You were the guy who bumped into me at the underpass! How you doing, bushy-hair?" Sento offered his hand to help Izuku up, which he gladly accepted. Izuku, now off of the floor, told the boy "My name is Izuku Midoriya! Can I ask who you are?"

Sento informed the young student "My name is Sento Kiryu, pleasure to meet you, Izuku!" At that bit of information, Izuku gasped and asked "Sento Kiryu? Like the Sento Kiryu who is the head of Touto Institute of Advanced Matter Physics?!" Sento gave Izuku a thumbs up and answers "Yup, though I'm having a friend look after the place for me while I'm away." izuku, curious about what the genius was doing at UA asked "What are you doing here at UA, Sento-Kun?" The genius grins and tells him "I'm starting my first day of my 2nd year here! I'm a student after all!" Izuku was largely surprised, but he then noticed that Sento was wearing the UA student uniform underneath his brown coat. Izuku followed up with "Which department are you in?" Sento told him "Class 2-A, hero course!"

After Izuku was done being impressed by his senior, a female voice called out to the genius "Sento! Where were you? We gotta get to class!" Approaching the two boys was Misora Isurugi, who was wearing a white jacket over her uniform as well as a pink scarf. Sento responded "Oh Misora! Sorry I wandered off, I was just coming back from the bathroom, when I bumped into this guy over here!" Sento gestured to Izuku. Misora noticed the green haired boy and asked "Are you new here?" Izuku nods. Smiling, Misora tells Izuku "I'm Misora Isurugi! Sento's girlfriend!" Izuku is stunned and looks to Sento to confirm this, and the genius says "Yup! She sure is!"

Misora then asks the first year "Are you lost? What course do you belong to?" Izuku tells her "Class 1-A, hero course!" Misora cheerfully shares with him "Sento and I were in that class last year, ah good times! Anyhow, you just passed the homeroom door, its three doors down behind you." Turning around, Izuku sees the large 1-A symbol on the door behind him and thanks the two "Thank you very much, you two!" Sento waves him off and says "No sweat, now hurry off to class! If I recall correctly, your homeroom teacher is a strict guy, so showing up late would get you in trouble."

Izuku runs off, but not before waving to the couple and saying "See you guys around!" Misora hooks her arm under Sento's and remarks "He's a nice kid, huh?" Sento replys "This might be an interesting year after all!" Misora then dragged Sento along with her using her arm strength and told him "Now we should be heading off to class as well, Banjo and Kasumi are probably waiting for us!" Sento calmly agrees "Yes, dear." as the two head off to class 2-A.

 **(Music stops playing)**

* * *

 **Class 2-A Homeroom, 9:00 AM, UA High School**

As Sento and Misora were walking along, they stood in front of class 2-A's homeroom door. Sento, like a gentleman, held the door open for Misora to walk through. She said "Thank you Sento!" and he replied "My pleasure." The two of them weren't shocked to see their friends Banjo and Kasumi, sitting in the front as they were the only 4 students in the class. The pair noticed them enter and Banjo called out "Oh, hey you guys! About time that you showed up! You know, for such a genius, you really got a problem with being on time, you know Sento?" The young genius responded to his brawny friend "I'll have you know Banjo, that tardiness is the calling card of the true genius. Why do you think that Power Loader sensei isn't here yet?"

Sento then acknowledged Kasumi "Good morning Kasumi! I trust that you both are doing well?" Kasumi greets Sento in a friendly manner "Yes Sento, Ryuga and I are both fine, thank you for asking!" Kasumi then turns to her bestie Misora and excitedly asks "Misora, is that a new jacket that you're wearing? I haven't seen you wear that before!" Misora told her "It was a gift from my dad and Sento for the new school year!" Kasumi compliments her friend "Well, it looks amazing on you! Maybe we could go shopping and you could help me pick out something new to wear too! I hear that there's a big sale going on at the mall this weekend and I was hoping that you could come!" Misora tells her "Let's do that then!"

Banjo then interjects and asks Sento "By the way, I haven't seen Owner around lately. Is something going on with Mr. Isurugi?" Sento reveals "Owner has been very busy with a second job to help fund the café and has been giving Takumi some pointers over at the Institute. So, most of the time, he's very busy. He only comes home about once a week, and he gave me the money to get Misora her new jacket from his earnings at his other job." Satisfied, Banjo said "Well, alright then."

Just as the four friends sat in their seats and were done speaking, the pro hero Power Loader walked in. He was wearing a massive yellow helmet over his orange haired head, wasn't wearing a shirt, and sported grey gloves with metal hinges over his massive hands. He walked over to the podium in front of the student's desks and he placed a folder with some paperwork on it. Clearing his throat to speak, Power Loader addressed the class "Good morning, class 2-A. Today is your first day as second year students at UA. You four should already be familiar with me, but I'll reintroduce myself. I'm the pro hero Power Loader, and your homeroom teacher for the year."

Sento raised his hand "Excuse me, sensei?" Power Loader asked "Yes, Sento?" Sento inquired "Seeing as class 2-A consists of only myself, Misora, Banjo and Kasumi, how will classes work?" The teacher answered "Well, seeing as this is quite the small class, lessons will carry on as they would normally except for one thing." Power Loader pulled out a copy of the class syllabus from his folder "Listed in the syllabus, is our itinerary for the year regarding the academics. However, Principal Nezu suggested that for the practical side of class, that you four join class 1-A for all practical lessons. Actually, once I'm finished explaining everything to you here, you are to head over to class 1-A for their quirk assessment test that Aizawa will be conducting outside."

He continued "This is so the first years can see some of our more experienced students at work, as Sento, Banjo and Misora got their provisional hero licenses at the end of last year." Sento, Banjo and Misora nod at the mention of their status. Power Loader turned his head to address Kasumi "You Kasumi, are here due to Ryuga's personal request that you be in the same homeroom as your friends. Nezu approved this as soon as he saw both your grades and photon laser project that earned you an A+ in your support class. The fact that you got in through recommendation also helped." Kasumi beamed at the mention of her accomplishments and her classmates were visibly proud of her.

Power Loader added "For those reasons, Kasumi is to become UA's first ever support hero!" The teacher then proceeded to wrap things up "So before you 4 head out, here is a copy of the course syllabus." Power Loader gave Misora the papers and she passed them out. He said "Classes will begin in here with math first thing, except for today as this is the first day, then you'll head over to class 1-A for physical training, then you'll have lunch, and finally, you'll all come back here for the remaining classes. During your time with class 1-A, I'll be in my workshop, so if any of you need to see me, I'll likely be there." Power Loader then raised his right hand in a fist and said "Let me hear you say…" The class 2-A students shouted, "Plus Ultra!"

With everything taken care of, Power Loader was about to leave for his workshop, when he paused to say one last thing "Oh yeah, don't forget to show your juniors what you 4 are made of!" The students replied "Yes sensei!" With that, Power Loader left the classroom. Sento, Misora, Banjo and Kasumi gathered their things and exited the classroom as well. They began to make their way over to class 1-A. They walked by some class 1-B students on their way there who recognized them and were respectful of their seniors. Class 1-A would not be ready for what was in store for them.

* * *

 **Class 1-A Homeroom, 8:58 AM, UA High School**

Izuku had just made it to class with a few minutes to spare. He opened the door to see Tenya Iida arguing with Katsuki Bakugo. The strict boy waved his arms around in a robot-like motion and yelled "You can't just treat UA's desks like that! Don't you have any respect for property?" Bakugo simply stated "Look man, I'm not bothering anyone, so could you just let this go?" As Izuku walked in, the pair noticed only them, but the rest of the class saw Izuku as waved to Iida and gave Bakugo a thumbs up.

Walking up to his newly made friend, Iida excitedly proclaimed "I knew it! UA would be remiss to not take notice of your abilities, Midoriya-kun. I had faith that you would pass." Izuku told the taller boy "You as well, Iida-kun. Thanks for all the help during the exam." Their conversation ended as one Ochako Uraraka entered the classroom and snuck behind Izuku. She poked him in his right shoulder when he wasn't looking, spooking him a bit. Turning around to see who did that, Izuku was met with the lovely sight of Ochako in her school uniform.

The green haired boy thought _"Wow! She looks so pretty wearing that! Wait, pretty? Where did that come from? Anyhow, I've got to thank her for all of her help!"_ Izuku opened his mouth to speak with the brunette "Oh, that was you, Uraraka-san! Good morning!" The girl in front of him jumped up and down excitably and replied "Good morning to you too, Deku-kun! I'm so glad that you got accepted! I knew that you were hero material, what with the super punch!" Ochako imitated Izuku's punching motion, much to Izuku's embarrassment and the rest of class 1-A's amusement.

Whilst this was happening, Bakugo was deep in thought about Izuku being accepted. He had known Izuku since they were kids, and even though the boy was very kind and helpful, he wasn't what one would consider strong. He made a mental note to ask Izuku about things later.

"If the only reason any of you are here is to make friends, you're better off leaving UA right now." said a voice that came from right behind Izuku, Iida, and Ochako. The three students along with the rest of the class turned to the front door to find a black haired adult man, curled up in a yellow sleeping bag, which made him look like a caterpillar. The scruffy looking fellow drank a tube of yogurt, then proceeded to unzip his bag and stand up. He was wearing a black shirt and pants, as well as some kind of scarf around his neck. He said "Good morning class 1-A, this is the hero course." He walked into the classroom, stopping in front of the podium. He introduced himself "My name is Shota Aizawa, and I'll be your homeroom teacher for the year."

Izuku thought _"Since he's going to be our teacher, he must be a pro hero!"_ Aizawa pulled out a bunch of UA P.E. uniforms for the students and threw one at each of them. He stated "Time is very precious these days and we can't be squandering ours. Put on those uniforms and let's head out to the field." Class 1-A looked a bit unsettled, as none of them expected this on their first day.

 **UA Teacher's Lounge**

While Aizawa was instructing class 1-A, All Might, who was wearing a yellow teacher's suit, was reading over UA's teacher directory. The number one hero thought _"The curriculum is quite lax. It's very different from how normal schools operate. Even day one can be difficult if you're not ready. Hang in there, young Midoriya!"_

* * *

 **UA Practice Field**

Class 1-A was out in the field, as Aizawa told them to do. Their teacher revealed "We're doing a Quirk assessment test." The whole class piped up and yelled "What?!" Aizawa continued "Yes, that's right." Ochako questioned "What about an entrance ceremony? No orientation?" The other students nodded and Aizawa simply said "Heroes don't have time for frivolous things like that." Everyone began to murmur to themselves. Aizawa pointed out "The reason why UA is the top hero school and is thought of so highly, is due to the lack of restrictions regarding our traditions." The teachers also educate according to this as well."

He turned to the new students and asked "Besides, haven't you been doing something similar in school before coming here?" He held up his cell phone and it showed a chart, providing sample assessment test scores. He ranted "The Ministry of Education hasn't been using the results of people using their Quirks, so the numbers don't accurately reflect one's true worth." Aizawa turned to Bakugo "Bakugo, you scored top at the entrance exam. What's the furthest you could throw a softball in junior high?" The explosive boy answered "Roughly 67 meters."

Aizawa chucked a softball at Bakugo, who caught it, and said "This time, use your Quirk when throwing it." Katsuki made his way over to the throwing circle. Their teacher spoke up "Do whatever as long as you keep within the circle, give it 100% and don't dawdle!" Bakugo, seeing that he had free reign to go all out, did just that. He wound up his right arm and gripped the ball in his hand. He thought _"I'll add an explosion right before throwing!"_ Bakugo furiously shouted "DIE!" as the softball was sent soaring out of his hand like a cannonball being launched from a cannon.

Smoke was trailing from the flying object, and it finally dropped back down to Earth. Aizawa pulled out his phone to show everyone present how far Bakugo had thrown the ball. He said "The best way to be a hero is to know what your upper limit is." The phone showed that the ball had traveled 705.2 meters. Each one of the students was visibly impressed. One of the male students with blonde, almost lightning-like hair said "Seriously! That's far!" A taller girl with a black ponytail placed her right hand over her mouth and remarked "Goodness!"

 **(My Hero Academia OST – Bright and Cheerful starts playing)**

Someone remarked "Sensei! Who said that you could get started without us?" The class 1-A students turned to face the direction said voice came from, to be met with the sight of 4 people, two boys and two girls. The boy who made the remark was Sento Kiryu, wearing his trademark brown coat. Ryuga Banjo, who was sporting a blue and white jacket with a dragon design on the back. Misora, who was wearing her new white jacket and Kasumi, who was wearing a sky-blue jacket. The Build crew was on the scene.

Aizawa ignored Sento's comment and presented them "Class, these are the four students that make up this year's class 2-A. They're second years, which makes them your seniors. Please introduce yourselves to them." The students gave the second years their names.

"I'm Izuku Midoriya!"

"Ochako Uraraka, here!"

"Tenya Iida, upperclassmen!"

"Katsuki Bakugo."

"Eijiro Kirishima!"

"Yuga Aoyama!"

"My name's Mina Ashido!"

"Asui Tsuyu, kero."

"Maoshirao Ojiro."

"Denki Kaminari!"

"Koji Koda…"

"Rikido Sato."

"Mezo Shoji."

"Kyoka Jiro."

"Hanta Sero!"

"Fumikage Tokoyami."

"Shoto Todoroki."

"Minoru Mineta."

"Momo Yaoyorozu!"

With class 1-A having finished their introductions, Aizawa explained why the second years were with them "Class 2-A will be joining us in joint practical lessons as their class only consists of 4 students. Also, Principal Nezu seems to think that seeing your seniors up close and personal will give you all a greater sense of how far you all are to becoming real heroes." He added "Oh by the way, class 2-A, introduce yourselves."

Kasumi started "Hiya class 1-A! My name is Kasumi! I'm 16 and I'm one of the second-year students of class 2-A. I'm working towards becoming a support hero, the first to ever come out of UA!" Momo raised her hand to ask a question "Excuse me!" Kasumi looked at the girl and asked "Yes?" Momo proceeded to ask, "What does being a support hero specifically entail?" Kasumi smiled at the curious young lady and responded "Well Ms. Yaoyorozu, I am essentially aiming to become the kind of hero that supports other heroes. I've personally never been one for all of the glory and fame that is associated with being a hero," at this, Aizawa proudly nodded and silently agreed with Kasumi's point "however, I merely want to facilitate the work of our upstanding heroes and be a small part of the greater goal at large, keeping society safe from villains." Kasumi then grabbed Banjo's hand and brought up "Also, my boyfriend Ryuga here is a big reason for my dream! I want to support him every bit as much as he does for me!"

Momo and the rest of the class 1-A girls (minus Toru) had visible blushes on the faces and Ochako looked too similarly to a tomato. Mineta had a scowl on his face and the rest of the boys looked surprised. Asui was the only composed enough to ask, "So he's your boyfriend, ribbit?" Kasumi told the frog girl "Yup! The best one ever! Ain't that right, Ryuga?" At the praise, Banjo felt a bit embarrassed, but mostly happy at Kasumi's words. He decided to introduce himself "That's right! Hey there freshmen! I'm Ryuga Banjo, most people call me Banjo!" Kirishima looked at Banjo for a couple of seconds before pointing at him and shouting "Hey I know you! You were the guy who was the junior league boxing champ 5 years ago!"

Banjo confirmed that "Yeah, that's me." Izuku, Bakugo, Todoroki and the rest of class 1-A's boys looked at Banjo with a new level of respect. This guy was a boxer before he applied for UA. That meant he already knew how to fight. Kirishima followed up with "Why'd you quit and how did you make it into UA? I always thought that you were quirkless?" Banjo answered the red-haired guy "Easy, I quit because if I were to go pro, there'd be the chance that I could get punch drunk or get a career-ending injury and I would never want to put Kasumi through that." All of the girls went "Aww!" at Banjo's thoughtfulness towards his girlfriend.

Banjo picked back up "About that second question, I'm no longer quirkless, but I'm gonna let my buddy Sento answer that when it's his turn." Misora was the next to introduce herself "Hi there everyone, I'm Misora Isurugi! I'm 16 like the rest of my friends here and I'm going to be a professional rescue hero!" Izuku then raised his hand. Misora saw him and pointed at him saying, "Oh hi Izuku, nice to see you again! What's your question?" Izuku asked "Misora-sempai, you want to be a rescue hero?" Misora clasped her hands together in front of her and answered "Yup! It's been my dream ever since I was little. I really admire heroes like the Wild Wild Pussycats and Recovery Girl who help people in ways other than simply beating down the villains! They inspired me to want to do more for the innocent people who find themselves in need of rescue."

Ochako asked Misora "Misora-chan! How come you know Deku-kun?" Misora looked towards Ochako, smiled and asked, "Do you mean Izuku?" Ochako nodded to confirm this. Misora tugged at Sento and said "Well, earlier this morning before class started, I went to look for this one here, when I saw Sento talking to Izuku and we introduced ourselves. He got lost looking for the homeroom, so we showed him where it was, since we had been there last year!" Misora pouted and went on to say "Sento here is quite the day-dreamer and he always seems to be in his own head for way too longer for it to be healthy. So as his girlfriend, it's my job to keep him focused and on track!" Mina squealed and asked "You guys too? How romantic! Two couples from class 2-A!"

Sento stepped forward as the last one of class 2-A to introduce himself. He calmly said "Good morning, class 1-A! My name is Sento Kiryu. The four of us will be participating in physical tests with you guys for the year. As Mr. Aizawa mentioned earlier, Principal Nezu wants you all to see the difference between you guys and students who've been here at UA a year longer." Bakugo chose then to rudely comment "Hey! Just because you guys are second-years doesn't mean you're stronger than me!" Izuku interrupted "Kacchan, maybe you shouldn't say that to Sento-sempai?" Sento spoke up "While I appreciate that Izuku," Sento's eyes shined with a glimmer of confidence and strength as his resolve was palpable and all of class 1-A felt it "maybe I simply need to show Mr. Bakugo here how strong I can be."

 **(Music stops playing)**

Sento turned to Aizawa and asked "Mr. Aizawa, can I please attempt the same softball throw that Bakugo did a few minutes ago?" Aizawa grinned and threw one at the black-haired boy "Of course, that's why you four are here." Sento stepped into the throwing circle and Aizawa mentioned "Don't forget to use your quirk and don't hold anything back!" Misora, Banjo and Kasumi all waved at Sento, while class 1-A were all fixated on Sento. Aizawa explained to the class "Sento, Banjo and Misora's quirks all require the use of a device, so they can use it in training exercise. No comments about unfairness or cheating will be tolerated, got that?" The class collectively nodded.

* * *

Sento pulled out the Build Driver and placed it in front of his waist, the belt emerging from the Driver and wrapping around the boy. He pulled the Rabbit and Tank fullbottles and said "Now, let's begin the experiement." He began to shake the bottles up and down, everyone present could hear the rattling sound that the essences in the bottles made. Sento placed the bottles in the Driver:

 **RABBIT!**

 **TANK!**

 **BEST MATCH!**

Sento turns the lever on the Driver, causing two halfbodies, one red and the other blue, to appear. The Driver then asks:

 **ARE YOU READY?**

Sento said "Henshin!" The halfbodies snap together onto Sento, covering him in armor. The Driver announces:

 **FULLMETAL MOONSAULT!**

 **RABBIT! TANK!**

 **YEAH!**

Sento now transformed, turned to face class 1-A and said "Just to be clear, myself, Banjo and Misora all got our provisional hero licenses at the end of last year. With Kasumi for support," Kasumi smiled "We've been active heroes for a few months now, maybe you've heard of us? We're the rookie hero team, the Build crew!" Izuku gasped and blurted "The Build crew?! I've heard about you guys, you're a new hero group that's been in the news a lot recently for your consecutive successful wins over villains and criminals! Your group's placed at number 100 in all of Japan, even though you guys are new!" Sento brightened at Izuku's compliments "Well, seems you're quite well-informed Izuku! Yes, that's us and I'm the team leader Build, or use my official title, Kamen Rider Build."

Iida raised his hand to inquire "Excuse me Sento-sempai, what do you mean by Kamen Rider?" Aiwaza interjected and said "Just as it sounds Tenya, the device that Sento, Banjo and Misora use to transform is called the Build Driver, they use it to become "masked" or Kamen Riders." Sento looked over at Bakugo, who now regretted acting cocky to an already licensed and practicing hero, and said "Hey Bakugo and everyone else, take a good look at this and make sure not to blink!"

Sento, clutching the ball in his right hand, wound up a pitch and then faster than a pitching machine, shot the ball past the school's limits, into the sky. All of class 1-A were dumbfounded and amazed. Aizawa held up his phone, showing that Sento had launched the ball a total distance of "INFINITY?!" yelled all of class 1-A except for Todoroki, Tokoyami and Koji, the more silent students. Sero immediately questioned "How did you do that?" More than happy to oblige, Sento held the Driver on his waist and told the tape-boy "The Build Driver allows us to access the full power of our quirk, Nebula Gas, which is a transformation-type quirk. By increasing my power beyond normal human limits, I performed the feat you just witnessed and achieved an infinity on the test!"

Jiro posed her own question "You said our quirk right? Does that mean that the rest of your team has this quirk?" Misora was the one to answer instead "Not Kasumi, she's quirkless. But Banjo and I have the quirk as well!" Izuku decided to throw his hat in the ring "How can the three of you have the same quirk if you're not related to each other?" Sento, having left the throwing circle and disengaged his transformation, stood with his friends in front of class 1-A, and made a T with his hands, asking "Could we maybe address that some other time? As I recall, we all still need to finish Mr. Aizawa's quirk assessment test! I know! Mr. Aizawa!" Aizawa boredly looked over to Sento and said "Yes?"

Sento petitioned "If more than half of the class performs adequately, could we all go on a field trip to the Touto Institute of Advanced Matter Physics tomorrow?" Banjo chimed in "Oh! That's a good idea, Sento!" Aizawa was close to refusing the suggestion when Sento brought up "It'll keep you from having to teach them for a whole day!" Aizawa was sold on the idea and said "Okay, it's a deal. However, I'm expelling the student who scores the lowest total score of all 8 tests from class 1-A. You four are exempt as I'm quite familiar with your abilities, having taught you guys last year." Kasumi piped up "Aw! We love you too, Eraserhead-sensei!"

Class 1-A were shocked at the Erasure hero being their homeroom teacher. Mineta then spoke up and shouted "Wait! One of us is getting expelled? Not cool!" Aizawa glared at the boy and merely said "Whoever comes in last will be judged as having zero potential and is undeserving of being here, no exceptions." Momo then remembered something "Wait just a moment, Sento-sempai?" Sento said "Yes, Momo?" She eagerly asked, "Are you the same Sento Kiryu who is the director of the Touto Institute?" He held Misora's hand and said, "That would be me!" She questioned "Well, how come you are at UA?" He informed her "A good buddy of mine is running the Institute in my stead, while I lead the Build crew and attend UA. I actually plan to have the Institute double as our hero agency in the future!"

She bowed her head and said, "Thank you very much for the clarification!" Sento responded "No problem!" Bakugo, who had kept silent until now told Sento "Sorry about dissing you earlier, I didn't know that you were a pro hero." At this, Sento sighed, confusing class 1-A. Misora explained "See Bakugo, Sento here absolutely hates it when people look down on others. He feels like that's a sign of weakness in moral character and that could result in someone taking their first steps towards villainy." Wagging her right index finger like a teacher would, Misora told the whole class "Don't underestimate or belittle someone under any circumstances, because those tend to be the kind of people who end up proving you wrong."

With all of that out of the way, Aizawa resumed the assessment test.

* * *

 **(My Hero Academia OST – U.A. High starts playing)**

" **Test 1: 50-Meter Dash"**

Tenya was the first one to stand behind the starting line for the dash. He used his Engine quirk to speed himself forward as he raced towards the finish line. The robot standing by the end of the track clocked Tenya's run time as 3.04 seconds. Right behind him was Tsuyu, who reached the end by 5.58 seconds due to her hopping.

Next up were Ochako and Ojiro. The brunette girl used her quirk to lighten her clothes and shoes to make her be able to run a bit faster. Ojiro used his tail to launch his whole body forward, resulting in him getting 5.49 seconds. Ochako made a mad dash towards the goal and scored 7.15 seconds.

Aoyama and Mina were the next ones to run. Mina opted to run shoeless, to make the most use of her Acid quirk. Aoyama, on the other hand, simply turned his back to the goal. Mina used her quirk on her feet to slip and slide her way to the finish line, earning 5.00 seconds. Aoyama used his Navel Laser quirk to sporadically launch himself in quick bursts, clocking in at 5.51 seconds.

Izuku and Bakugo were next. As expected, Bakugo blasted his Explosion quirk from both of his palms to push himself through the air very rapidly and controlled very well. Over where the Build crew were observing the first-years, Sento commented "Oh, it seems that Mr. Bakugo is not completely the hothead I initially pegged him to be! He's showing a lot of control and resourcefulness in using his quirk." Misora chimed in and said, "Don't forget about Izuku right behind him!" As the girl stated, Izuku was about a foot behind Bakugo, without using One For All. The green-haired kid thought _"It's a good thing that I've been subconsciously continuing All Might's training plan during my down time, or I'd be in trouble!"_ Sento grinned widely and replied to his girlfriend "I didn't forget about Izuku, on the contrary, I predict that he'll make the top 5 in his class in terms of scores." Banjo said, "The little guy is determined, that's for sure!" Kasumi agreed "That's an understatement." Bakugo finished in 4.03 seconds, while Izuku scored 4.50 seconds. Bakugo was taken back by how close Izuku had managed to get on him.

Meanwhile, Izuku worried about the rest of the assessment _"This is only the first test, there's still 7 more to go! I have to use One For All on the hardest test to maximize my score so I won't be the one sent home."_ He heard some whooping and cheering being directed at him. He turned to see who it was, and he saw Ochako and Tenya yelling cheers of encouragement and over by the second-years, he saw the Build crew all wave at him, with proud smiles on their faces. The rest of the class 1-A students finished the dash, which left only class 2-A.

Banjo and Kasumi stepped up to the starting line. Banjo pulled out his Build Driver and put it on. It fastened the belt around him and he then yelled out "Come!" Flying down from UA's roof, was Banjo's Cross-Z Dragon. Class 1-A were wide-eyed at the sudden appearance of the mini machine dragon and yelled out "EEHHHH?!" Sento stepped forward to explain "You all remember how I transformed earlier?" The students nodded. "Well, I used two bottles to start the process." He pulled out the Rabbit and Tank fullbottles, showing them to class 1-A.

The genius continued, "These are called fullbottle and they contain the organic and inorganic essences of things that exist in the world. When an organic and inorganic bottle with perfect compatibility are used to transform, you get what we refer to as a "best match"." He pocketed the bottles and added "However, Banjo's bottles came with a bit of a dilemma. You see, his organic bottle is Dragon and the matching inorganic bottle is Lock. We found that the Dragon fullbottle is far too powerful to use as a best match as the Lock fullbottle acts to suppress the dragon half instead of working with it." He turned to see Banjo catch Cross-Z Dragon in his hand, Kasumi petting it and talking to it. He told the class "That's why I created Cross-Z Dragon, so that Banjo could transform with only one fullbottle! His strength is on par with or even exceeds some of the best matches, so he can keep up."

Shoto, who normally wouldn't speak much, asked Sento "How many of these fullbottles are there?" Sento was excited, he knew who Todoroki was and it pleased him that the boy was so curious. Sento answered "About 60 fullbottles in total, but we're on the verge of being able to create more. More about that subject at tomorrow's field trip, should enough of you guys pass!"

Back to Banjo, he pulled out the Dragon fullbottle and shook it up and down. He placed the bottle in the top of Cross-Z Dragon, then folded its head and tail in, changing it to adapter mode. He put Cross-Z Dragon into the Driver, which announced:

 **WAKE UP!**

 **CROSS-Z DRAGON!**

Banjo turned the lever on the Driver, which produced two blue halfbodies and asked:

 **ARE YOU READY?**

Banjo replied "Henshin!"

 **WAKE UP BURNING!**

 **GET CROSS-Z DRAGON!**

 **YEAH!**

Banjo stood proudly, having transformed into Kamen Rider Cross-Z. Kasumi was fiddling with her shoes. This confused class 1-A until Aiwaza explained "Kasumi is allowed to use all manner of support items as she does not possess a quirk. She is permitted to use her motor shoes, which she invented, to improve her performance. Normally this wouldn't be allowed, but that girl is very talented and creative. Principal Nezu was right to grant her a recommendation." Class 1-A gawked at Kasumi, the principal considered her to be a recommendation worthy student!

Banjo sped out like a bullet, reaching the goal in 1.00 second. Kasumi's motor shoes made her breeze across the track as though she was weightless, and she clocked in at 1.67 seconds. Next up were Sento and Misora. Sento transformed into his RabbitTank form while Misora pulled out her own Build Driver as well as her white Dove and pink Plane fullbottles. She shook them and placed them in the Driver, which announced:

 **DOVE!**

 **PLANE!**

 **BEST MATCH!**

She turned the lever on her Driver, which produced white and pink halfbodies, and then asked:

 **ARE YOU READY?**

Misora said "Henshin!"

The halfbodies snapped onto Misora, encasing her in armor. Her Driver announced:

 **HIGHFLY CLEARSKY!**

 **DOVE! PLANE!**

 **YEAH!**

Sento had become Kamen Rider Build and Misora turned into Kamen Rider Rescue. Mina energetically spoke up and asked "What's with Misora's armor? It looks so cute!" Ochako nodded in agreement. Kasumi was the one to answer, "That is Misora's base form, Kamen Rider Rescue, DovePlane form!" Sento was clad in his red and blue armor, a blue tank for his right visor and a red rabbit for his left. Misora was sporting pink and white armor, a pink plane for her right visor and a white dove on the left. She resembled Build's appearance, albeit with a more feminine figure and a pink skirt.

Build and Rescue took off towards the goal line, resulting in Sento clearing it in 0.90 seconds and Misora finishing in 1.00 seconds. Having disengaged their transformations, Misora good-naturedly bopped Sento on the head and complained "Man, you're still a bit faster than us Sento!" The genius responded "Sorry Misora, you're quite familiar with how fast RabbitTank form lets me move." She smiled and said, "That's good though, that just means that you can help us and others all the sooner!" Sento chuckled "That's true."

The rest of the exams proceeded as scheduled.

 **(Music stops playing)**

* * *

" **Test 2: Grip Strength Test"**

The second began with Sento using GorillaMond form to score 1000 kg, astounding all the first-years. The rest of the tests went pretty well. It was finally time for the softball pitch test, Sento and Bakugo were exempt because they already did it. Ochako, Banjo, Misora and Kasumi all scored infinity on the throw, due to Ochako's Zero Gravity quirk, the power of the Rider System, and Kasumi's power glove item. Everyone else in class 1-A made their throws, with Mineta scoring the lowest at 1 meter, an embarrassing show to be certain. Izuku was the last one to attempt the pitch. Aizawa was scrutinizing him in particular, as the teacher was staring at the green-haired boy quite intently.

 **UA Teacher's Lounge**

As All Might continued to read over UA's guidelines, he came across class 1-A's lesson plan. His eyes threatened to jump out of their sockets when he saw who their homeroom teacher was and said "Crap! The kid got Aizawa. He might try to expel young Midoriya today!" All Might closed the book and stood up, his mind made up. He decided to go and see how his chosen successor was faring. As he was running to the field, All Might thought _"Please, don't hold back young Midoriya! Your dream is right in front of you!"_

 **UA Practice Field**

Izuku thought to himself _"There's only this test, the long-distance run, sit-ups and the seated toe-touch left. I don't think that I'll come in last, but I really want to visit the Touto Institute! Eraserhead-sensei said he'd take up Sento-sempai's offer for a field trip there. I really want know more about the Build crew's Nebula Gas quirk."_

Izuku was about to use a 100% smash to rocket the ball out of the sky, when as he threw the ball, he couldn't feel the power of One For All. The ball merely flew a couple of feet and fell to the ground. Izuku asked aloud "What happened?" Aizawa chose to speak up "I erased your quirk." Everyone turned to Eraserhead to see that his eyes were glowing red and his capture scarf appeared to be floating on its own. He explained "My quirk is Erasure, which lets me turn off other people's quirks." He added "The examiners made a huge mistake in admitting you."

Aizawa continued "You have zero control over your own quirk, right? Are you going to one of those people who constantly break themselves, worrying their friends, loved ones and comrades? If you are, I'll expel you this instant!" Izuku spoke up "I don't intend to do…" Aizawa's capture scarf wrapped itself around Izuku and dragged him over to in front of his teacher. Eraserhead admonished his student "If you act recklessly with that power, I won't allow you to become a hero."

Sento approached the pair and said, "Wait just a moment, sensei!" Aizawa let go of Izuku and asked, "What is it, Kiryu?" Sento crossed his arms and said "Don't demoralize the kid. We don't know his personal circumstances. Maybe he simply has poor quirk control naturally! In that case, it is UA's responsibility to teach him proper control." Aizawa looked at Sento for a few seconds, then asked, "Then what do you suggest?" Sento bowed at a 45-degree angle and pleaded "Give me a minute to instruct him, I'll show you that Izuku isn't a waste of time!" Aizawa complied "Fine, but if he doesn't score above 500 meters, you have write me a 20-page essay about quirk control." The rest of the students, class 2-A included, seemed worried for Sento. He simply grinned and said "Ok!"

Sento calmly walked over to Izuku and asked "Izuku, what kind of quirk do you possess?" Izuku told him "It's a strength-enhancing quirk. I don't have much control over it. I've tried everything to fix it, but nothing has worked so far." Sento pulled his hands on Izuku's shoulders and told him "Look, I want you to picture a rubber band when you're about to use your quirk. Imagine it stretching out very far, but not snapping. I'm sure that image will help you exercise some control!" Izuku confidently nodded and said "Ok Sento-sempai, I'll try!"

 **(My Hero Academia OST – You Say Run starts playing)**

As Sento went back to his friends to observe Izuku's pitch, the green-haired boy gripped the ball and thought about what Sento told him. Meanwhile, All Might was hiding behind one of the buildings near the practice field, observing Izuku and the class. Izuku thought to himself _"Aizawa-sensei is completely right. A hero is someone capable of helping others and not being a burden. I have to prove my worth!"_ He channeled One For All's power in his right index finger only, the red veins of power becoming visible. He kept the visual that Sento gave him at the forefront of his mind and threw the ball yelling:

 **SMASH!**

The softball zoomed out of Izuku's palm, shocking all of class 1-A, Aizawa, and All Might. The only ones not surprised were the Build crew, who looked eager. As the ball landed somewhere far off, Aizawa looked down at his app he used to record the distance. He held it up for all to see and it read 705.3 meters. Ochako shouted "Yay Deku! Way to go!" Tenya agreed with his brunette friend "Yes, fine showing Midoriya!" Izuku, gripping his right hand with his index finger only slightly sprained, turned to Eraserhead and told him "I can still continue, Aizawa-sensei!" Eraserhead sported a full-on grin and said, "This kid!" All Might, who was still hidden, thought _"It seems that young Kiryu showed Izuku how to use control. Excellent! Principal Nezu made the right decision in having class 2-A help out. Seriously though, young Midoriya, you've surprised me once again!"_

 **(Music stops playing)**

* * *

Bakugo's world had been turned upside-down. He began to question everything that he thought he knew about quirks and power. First was finding out that their teacher Eraserhead, could turn off people's quirks. Then he was met with the rookie team, the Build crew and their literally overpowered quirk. The biggest upset was Izuku's display of power that rivaled his own. He thought _"That nerd was lower than even normal people! Was he a late bloomer? Or did he never reveal his quirk to anyone, hoping to have it as a secret weapon? How did he even pass the entrance exam then? I'm definitely gonna talk to him about this later."_

Aizawa looked over to Sento and said, "You know, when you retire someday, you would make an excellent teacher." Sento replied "Yeah, I keep hearing that a lot. It's certainly one path I might take down the line. For now though, I'm just glad I was able to help someone who needed it." Aizawa sighed and reluctantly said "You don't have to write the essay." Sento simply thanked the erasure hero.

After the rest of the exams were done, everyone was standing in front of a large monitor. Aizawa was tallying everyone's scores and Izuku, Ochako and Tenya approached the Build crew. Izuku thanked Sento "Sento-sempai, thank you very much for the help! I might have been in trouble if it weren't for you!" Tenya added his opinion "Yes, it was very commendable of you to help Midoriya!" Ochako also spoke up "Thanks for helping Deku-kun!" Sento told the three "You're all very welcome! Now, let's hope that enough of you guys did well enough to earn that field trip!"

Aizawa finished summing up everyone's total scores and displayed them on the monitor. 1st place went to Sento, with Banjo in 2nd, Misora in 3rd and Kasumi in 4th. Amongst class 1-A, Todoroki earned 5th place, Bakugo 6th, Momo in 7th, Izuku in 8th, Tenya in 9th, Ochako in 10th and so on. In last place, was Minoru Mineta. Aizawa looked at him and said, "Okay Mineta, you earned last place which means that you are expelled. I'm not doing this out of any sort of maliciousness, so you will have the option to either reapply to UA or go to another hero school. Understand?" The grape-haired boy nodded and walked off.

Aizawa turned to address his students "With Mineta gone, this leaves a vacancy in class 1-A's roster. Someone from one of the other courses will likely transfer in once it's time for the Sports Festival." Tsuyu raised her hand and asked "Sports Festival, kero?" Aizawa said "Don't worry, I'll explain more about that once it's here." Eraserhead then brought up "I can now see the benefit of having class 2-A involved in joint-tests with us, so here's what we'll do. If any of you have something you want to ask your seniors here, feel free to approach them. If that's okay with them." Kasumi smiled at Aizawa and class 1-A and said, "We're fine with it, it'll give a chance to learn more about our underclassmen!"

Aizawa reminded them "Oh yeah, since more than half of the class performed well, we can go on that field trip Sento spoke about, so no class tomorrow. Be sure to meet up in front of the school at 8:50 AM, as we'll be leaving by bus at 9. Before Aizawa walked off, he stopped in front of Izuku, who seemed a bit intimidated by the scruffy man. He wrote on a slip and handed it to Izuku, saying "Go to Recovery Girl and give her this. She'll treat your sprained finger. Also, sorry about singling you out. I just had to be sure that you were totally committed to UA's standards." Izuku replied "Don't worry Aizawa-sensei, I understand. I'll work hard, promise!" Aizawa smiled and said "Good."

All of class 1-A minus Bakugo and Todoroki began to swarm class 2-A with questions. Things like their favorite color, favorite foods, hobbies, typical teenage stuff. As Aizawa was heading off to take care of some paperwork, All Might emerged and said "Aizawa-kun, that was a bit unnecessary, don't you think?" Eraserhead turned to the number one hero and responded "I did what I felt was needed to get the most out of them. Those kids could be amazing heroes if they're nurtured properly, so I'm going to work them to the bone." All Might then cheekily pointed out "So that's why you focused on young Midoriya then, to see what he was capable of!" Aizawa smirked and responded "The kid's heart is in the right place, but to be a pro hero, you need more than just heart. You need skill, plain and simple."

All Might reminded Eraserhead "Young Kiryu seems to have an excess of that then, as he aided young Midoriya and showed him control!" Aizawa had a proud look on his face and said "That's why I didn't fail Izuku. Heroes need to learn a simple, but very overlooked rule. Asking for help isn't a sign of weakness, it can lead to greater strength." Toshinori grinned and said, "I think we're going to get along just fine, Aizawa-kun!" Aizawa simply sighed and responded, "Looking forward to how you'll fare, All Might."

* * *

Classes had finished for the day. Izuku had gotten his finger checked out by Recovery Girl and he was feeling better. Her quirk did sap a bit of his stamina, so he was feeling a bit tired. As he was making his way to the exit,

Tenya ran up and called out to him "Midoriya!" Izuku stopped and waited for his friend. He asked, "What's up, Iida?" The older boy made robotic movements with his arms and pointed to Izuku's finger "Is your finger all better?" Izuku nodded and said "Yeah, Recovery Girl sure is amazing!"

The pair were interrupted by Ochako, who was running towards them. She shouted "Hey, hold up guys! Wait for me!" The boy did as she asked and waited for her. Now in front of Izuku and Iida, Ochako cutely smiled and said "Boy, today was full of surprises, huh? Especially you, Deku-kun! That pitch was strong!" Iida was just then reminded of something and asked Izuku "Midoriya, why does Bakugo call you Deku?" Izuku shyly admitted "It's an insult towards me. He means Deku as in can't do anything."

Ochako piped in and raised both her fists "It can also be like Dekiru, like I can do it! I like Deku, it could be your hero name!" Izuku blushed crimson and looked away saying "You can call me Deku!" Iida was astounded "I thought you said it was an insult?" Izuku could only say "My world's been thrown out of whack." Ochako blankly stared at the two with a question mark over her head. As the three were about to walk to the bus stop, They saw someone familiar leaning on the front gate.

Bakugo was standing there, waiting for Izuku. The explosive boy had a serious look on his face and asked Izuku "Can we talk, Deku?" Iida and Ochako were about to object, having been told by Izuku what Bakugo did to him when they were younger. However, Izuku placed a hand on each of their shoulders and told the pair "You two go on without me, I just have to talk about some stuff with Kacchan. I'll see you guys tomorrow on the field trip!" Izuku's friends reluctantly left him with the blond-haired kid. Izuku turned to Bakugo and told "If we're going to discuss this, we have to see All Might as he's involved as well." That certainly caught Katsuki's attention, causing him to stop leaning on UA's front gate and tell Izuku "Well lead the way, nerd."

* * *

 **Faust Underground Hideout, Touto**

Night Rogue was personally overseeing the mass production of more Smash creatures for Faust's forces. He quickly noticed that a purple portal of some kind had formed a few feet away from him and pulled out his TranSteam Gun. He pointed it towards the portal, from which someone wearing a suit and tie whose body resembled the portal walked out alongside a man with light blue hair and hands everywhere on his person. With his gun still trained on the two intruders, he angrily demanded "Who are you both, and what are you doing here!"

The man with the hands around him introduced himself "My name is Shigaraki Tomura, and this is my partner Kurogiri. We belong to the League of Villains." Kurogiri curtly bowed and nodded in agreement. Night Rogue briefly lowered his TranSteam Gun and said "I've heard about you guys. You're trying to remove heroes from society and kill All Might." Shigaraki creepily grinned and replied "That's right! I'm here because I'm looking for some allies and my sources told me that Faust might be a good fit to work with us." Night Rogue spent a few moments silent, then asked "And what makes you think that we want anything to do with you?"

The sound of metal feet walking towards the three echoed as they became louder. The source of the noise was soon made evident as on the stair railing above them stood Blood Stark. The villain was fitted in a blood-crimson suit with pipes sticking out of it and a cobra-shaped teal visor on his face and a teal cobra symbol on his torso. His own TranSteam Gun was holstered at his side. Stark mused "Why so hasty, Night Rogue? I'm sure that our friends here didn't come all this way for nothing."

Shigaraki took one look at Stark and remembered something that his mentor had shared with him. He pointed at Stark and said "You're Blood Stark! Sensei mentioned you, he said that you were one of his most powerful and useful comrades in the early days!" Blood Stark sighed and confirmed "Correct! That mentor of yours is one of my dear old friends from back when quirks first emerged. We sure raised a lot of hell together. You calling him sensei confirms for me that he must have sent you my way to assist you, right?"

Shigaraki nodded and Kurogiri requested "If you could please, Blood Stark-sama!" Stark was grinning under his helmet, things were finally starting to take off. Soon nothing would able to stop what was coming. He walked up to Night Rogue and told him "Night Rogue, these two are valued guests here in Faust. We're going to be working together with them, so do try to get along?"

Night Rogue nodded and Stark turned to Shigaraki, asking "Shigaraki-kun, do you think that you could set up a meeting for myself and your mentor, my old friend, All For One?"

* * *

 **A/N: There's the chapter after what feels like forever. I'm working on the next one and I'll post it when I've finished. I'm going to hold a poll for the next chapter about something that happens. The Touto Institute is going to be attacked during class 1-A's field trip there. Someone is going to show up and cause problems. Who do you all think should be the attacker? The choices are:**

 **A Smash powered by an essence**

 **Night Rogue**

 **Blood Stark**

 **The poll will close at 12:00 AM Saturday January 12, 2019, so vote now!**

 **Thank you all and I hope to see those results soon, DarkAbyssBreak out!**


	10. A Trip to Remember

**I'm back with the next chapter of the story! Sorry that I've been gone for quite a while, school and life in general kept me busy. I finally have time to sit down and continue this story, now that I'm done with school until September. This chapter will be a big one as an apology for taking so long. The results of the latest poll are in and the winner was decided. The villain that will attack the Touto Institute of Advanced Matter Physics is an Essence-enhanced Smash sent by Faust. From re-watching Kamen Rider Build, I know exactly which essence I want the Smash to have.**

 **This chapter is going to see class 1-A accompanied by the Build crew, go on the promised field trip to the Touto Institute. A lot of background information about the Build crew, the Rider System, the Pandora Box and the fullbottles will be touched on this chapter. Sento and his friends are going to show class 1-A all that the Institute has to offer, as well as answer any questions the first-years may have for them.**

 **Some previously established characters will be returning this chapter, as well as some new ones. Where the plot of this story is concerned, I plan to mainly follow the path of My Hero Academia's canon but diverging in some ways to incorporate the Build crew. Some events that happened in Build will happen here, and some will be different. Lastly, there's the matter of Bakugo pressing Izuku for some answers last chapter. That's going to be addressed here.**

 **I'm happy that my first story on this site is shaping up like it is! I plan to have some more polls for ideas for what should happen in future chapters. Keep an eye out for them!**

 **I do not own Kamen Rider Build, My Hero Academia, or any of the soundtracks mentioned.**

 **Without further ado, here's the chapter!**

* * *

 **A Trip to Remember**

 **UA Teacher's Lounge**

All Might had just come back from discussing the joint exercises done between class 1-A and class 2-A, the Build crew. Aizawa had informed him that due to how well the students performed, that he got the ok from Principal Nezu to conduct the field trip that Sento had suggested. The young genius assured Nezu, Aizawa and All Might that he and his staff over at the Touto Institute would take very good care of the students. Lunch would be provided to the visitors and the trip would be quite educational. Sento did have one very important condition, however. He told Nezu and the two teachers that the students would have to sign a waiver once they arrived at the Institute. The document would outline that class 1-A are not to share any details about what they witness and learn about whilst at the facility.

Nezu readily accepted the terms, as he was very much aware of the Pandora Box in Sento's possession and how valuable it was to not only Touto, but Hokuto and Seito as well. The principal was aware that one doesn't need to be a genius to recognize the potential risk of some governmental body or a criminal going after the Box after hearing about it. After reviewing the waiver provided by Sento for a few minutes, Nezu gave his approval and promptly left to drink some tea and do principal things.

All Might, alone in the lounge, sat down in an empty chair and drank from a water bottle. The hero thought to himself _"I'm happy that young Midoriya didn't get expelled. That would've made it harder to properly train him as my successor! I must thank young Kiryu for his timely assistance. If he is anything like Izuku, maybe he would appreciate an autograph from your's truly!"_ Toshinori was pulled out of his thoughts by the sound of the teacher's lounge door being opened. He turned to see Izuku, who was looking like a kid who got caught with his hand in a cookie jar, and Bakugo, who was eerily calm. The two students approached All Might.

All Might greeted the two "Ah young Midoriya and young Bakugo! What are you two doing here? Is there something that I can help you with?" Izuku decided to tell his mentor what was going on "All Might, Kacchan here is curious about how I have a quirk now and he wouldn't let it go. I brought him here so that he can hear it from you. I promise he won't tell anybody, we can trust him." Bakugo was surprised that Izuku still held him in such regard after his past treatment of the guy.

All Might frowned for a moment, then said "Young Bakugo, I'm only telling you this secret because young Midoriya believes that you are trustworthy. I'll ask that you keep whatever I tell you here a secret. Amongst the students, only Izuku knows this and amongst the staff, only myself, principal Nezu and Recovery Girl know. So, can I trust that you'll abide by my conditions?" Bakugo squinted his eyes and stared right at All Might. He eventually said "Fine. If it's you who's asking, I can agree to that, All Might." All Might sighed "Good, I'm relieved to hear that. Let's start with this." Suddenly, the number one hero deflated in a puff of smoke, and Toshinori's skinny form was left in his place. Bakugo visibly recoiled and shouted, "What the heck!" Izuku walked over to Bakugo and made a hand gesture signaling to lower the volume "Kacchan, not so loud."

Bakugo pointed at All Might and asked, "What happened to you?!" Toshinori stood up from his chair and lifted his shirt, revealing his monstrous injury. Bakugo placed his hand over his mouth, almost gagging at the sight of it. After allowing the boy a few seconds to collect himself, All Might explained "This is an injury that I got from a villain a couple of years ago, he almost killed me. That said, I also managed to mortally wound him as well. Sadly, that monster got away from us." Bakugo was frightened "There's a villain out there who's on par with you?" Toshinori nodded.

The pro hero pointed at his stomach and continued "Due to this complication, I can only safely perform my hero duties for about 3 hours a day. The doctors have told me that anymore than that could put my life in danger. As the symbol of peace, I can't risk my untimely demise without ensuring that the world is left in good hands." All Might confidently looked at Izuku and Bakugo "That is why I accepted the principal's offer to work here at UA as a teacher." He solemnly turned to the boys and said "Young Bakugo, Izuku was indeed quirkless as you once knew, but I gave the boy my quirk. If we are being specific, I passed on my quirk to young Midoriya."

Bakugo immediately exploded "What?! You can pass on your quirk? Why did you pick useless Deku here?!" All Might shot an angry look at Bakugo, which made the blond-haired student cower. The hero explained "I chose Izuku because to me, he embodies the true spirit of heroism. You recall how he risked his well-being to save you during the sludge villain attack?" Bakugo hated to be reminded of the incident but nodded in understanding. Toshinori continued "I was originally going to choose one of the other students here at UA who already had a quirk, but after meeting young Midoriya here, I changed my mind."

All Might glanced at his successor, who was misty-eyed by all of the praise that All Might was giving him, the praise that his mother, classmates and peers all should have given to him when he was younger. The hero stated "I chose Izuku because my quirk One For All, is the combined power of all who have ever carried this torch. I am the 8th user of One For All and young Midoriya here is the current holder, the 9th." Bakugo was starting to put the pieces together. With a look of realization on his face, he asked All Might "You were like Deku, you used to be quirkless too, weren't you?" The number one hero told the boy "Yes, I was. My master who was the 7th holder of One For All, entrusted this quirk to me after she saw that I wanted to be a hero more than anything."

Bakugo finally asked "Why didn't you give your quirk to someone like me, or Todoroki or pony-tail Yaoyorozu?" All Might smiled at the question and plainly told Bakugo "Because none of you NEED it." Bakugo's face paled at the statement and he finally looked at Izuku since entering the room. The green-haired boy's face was a weird mixture of embarrassment, shame, and weakness. All Might continued "You all have such amazing quirks and other skills! Meanwhile, young Midoriya was put down by those around him merely because he lacked a quirk." All Might slammed his fist on the nearby table, startling the two boys "That isn't right, those aren't the sort of people that I give more than my all to save. We cannot look down on the quirkless simply because they don't have powers, that is discrimination."

Bakugo felt ashamed of himself, he pressed Izuku into getting All Might to explain things to him, even though it was none of his business. Doing something that felt very foreign to him, Bakugo turned to Izuku and clearly said "I'm sorry." Izuku blinked, not expecting to hear that from him "Huh?" Bakugo told them both "I'm guilty of messing with Deku because he didn't have a quirk. Everyone told me that I was special because I was born with an amazing quirk, and Deku was left behind because he didn't. Now, I find out that people can get quirks passed on to them, that's nuts." Bakugo pulled a nearby chair over to him and sat down, putting his hands on his knees "Don't worry you two, I'll keep this secret. I'm no blabbermouth and I figure that this information is really sensitive cause All Might's quirk is one of the strongest one's out there."

Bakugo remembered something else he wanted to ask, "How did you pass on One For All to Deku?" All Might supplied "One For All is transferred through the exchange of DNA, along with the consent of the current holder. I had to be willing to pass on my quirk to young Midoriya." Bakugo, now satisfied with the situation, walked towards the door. Before he exited, he said "All Might, I respect the hell out of you. You're our symbol of peace, the number one hero. If you believe that Deku is worthy of your power, I'm not going to argue. As for you Deku, now that I know this, we're rivals. We both always wanted to become heroes and now that you have a quirk, you might just do it. If you wanna be number one, just know that I'm shooting for the top spot too." Izuku, awed at the change in his friend, said "You got it Kacchan, Plus Ultra!" With Bakugo now headed home, Izuku told All Might "I'm really sorry, All Might! I saw that keeping this secret from Kacchan was causing problems and I wanted to fix that."

All Might grinned widely and placed his hand on his protégée's shoulder "That's quite alright, young Midoriya! Young Bakugo gave us his word that he'll keep things secret, and besides, if someday the truth of One For All were come out, you'll have people who know and can help you." Izuku smiled and said, "You always know just what to say, All Might." The hero countered "Not always young Midoriya, but I sure do try! HAHAHA!" Izuku headed to the door and said "Well, I guess I'll get going. See you after tomorrow!", he left the lounge and headed home.

* * *

 **Nascita Café, 8:00 PM**

Sento was washing some dishes from the dinner that he and Misora had shared together. They had sat down to a delicious meal of grilled mackerel, tamagoyaki and rice. Misora had long since gone to the bathroom to shower, then to bed. The young genius took some time while rubbing a plate with a sponge and rinsing it off to think about the field trip. _"I'll be sure to answer everyone's questions during tomorrow's trip. I'm glad that principal Nezu helped me draw up the Non-disclosure agreement forms, his work is very thorough!"_ Just as Sento finished putting away the now clean dishes and fixed up the café, he heard the bell ring as the front door opened.

The person who opened the door was Mr. Soichi Isurugi, better known to the community as Owner. He had a copy of the café's key on him and used it to get in. Owner saw Sento and greeted him "Yo, Sento! I see that you and Misora-chan have been running the café quite well." Sento shot Owner a look that came off a bit snarky and replied "Well I should think so, Owner. That second job of yours pretty much puts Misora and I in charge here." Owner smiled good-naturedly and said, "I'm very proud of you two, not only for running Nascita, but also for getting into UA and starting your hero team!"

Sento returned the smile and said "Thank you Owner, that means a lot! Also, Misora sends her thanks for the new jacket, she loves it!" Soichi rubbed his right hand behind his head and shyly said "Is that right, I'm glad that my little girl loved the jacket we both got her. By the way, thanks for helping me pick it out! I know next to nothing about fashion." Sento came up to Owner, placed a hand on the man's shoulder and said, "I only used the information that I got from listening to Misora on our dates."

At the mention of dates, Soichi adopted a smug look on his face and said, "So, you've been hanging on Misora-chan's every word, am I right?" Sento's face immediately turned bright red, he removed his hand from Soichi's shoulder and the young man quickly replied, "Of course I do, Misora is my girlfriend!" Soichi walked over to the counter and sat in one of the stools. He turned to Sento and told him in a father-like tone, "I'm glad that she is. She's got the nicest guy in the world looking after her." Sento got a bit misty-eyed after hearing the approval of his godfather, "I appreciate you saying that, Owner!"

Soichi then asked, "Is Misora-chan asleep? I noticed that she isn't here with you." Sento told him, "Yeah, she wanted to turn in early for a field trip we have tomorrow." Curious about this, Owner asked, "Oh? Where are you guys going?" Sento excitedly replied, "I got Aizawa-sensei to agree to have the field trip at the Institute! Incidentally, one of the first-years from class 1-A who will be joining us seems to be quite the curious guy!" Soichi seemed interested in what Sento was saying, "Well, who's this guy you seem so impressed by?" Sento answered, "His name is Izuku Midoriya. I gave him a hand today when class 1-A were taking the quirk assessment test. He had several questions about my quirk and the Build Driver."

Owner asked Sento, "You going to have the students sign a Non-disclosure agreement, right?" Soichi removed his glasses from his face and placed them on the counter in a rare moment of seriousness and continued, "We can't have either Hokuto or Seito get their hands on the Rider System, much less the Pandora Box itself. It would be utter chaos." Sento sat in the stool next to Owner and said, "I agree, but principal Nezu and UA's teachers assured me that class 1-A will keep this a secret. I mean, if we can't trust the next generation to take care of things, then what's the point?" Soichi grinned and said, "That's true enough!"

Owner then stood up and asked, "Say Sento-kun, would it be alright if I were to come along on your little field trip?" Sento gawked at the request and asked, "Why? Aren't you busy with your second job?" Soichi flicked his hat and said, "I've got a few vacation days saved up, so why not use one tomorrow so I can meet these future heroes that you seem to think so highly of?" Sento asked, "You're absolutely sure?" Owner pretended to be put off by Sento's question, clenched his heart and said, "Ah! Little Sento seems to not want his dear old godfather to embarrass him in front of his juniors!"

Sento held his hands up in appeasement and told Owner, "No, that's not it. You're more than welcome to join us, Owner!" Soichi then clapped his hands and proclaimed, "Bravo! It'd be fun to see how the Institute is progressing. I can hardly wait to see Takumi, Banjo, Kasumi and the other employees! We'll make a day of it." Sento laughed and told the man, "Sure, why not? Tomorrow is supposed to be fun and educational anyways." Sento looked over at the clock, which now read 8:50 PM and said, "We depart from UA by bus. We have to be at UA's front gate by 8:50 AM, then we'll head for the Institute at 9 AM after Eraserhead has made sure that everyone is on board."

Sento yawned and told Owner, "Anyways, it's getting late and I'm going to turn in. Good night, Owner!" Mr. Isurugi waved to Sento and said, "Good night, Sento."

* * *

 **Front Gate, 8:30 AM, UA High School**

Sento, Misora and Soichi were waiting by the front gate. They had breakfast, then immediately rushed off to UA. They didn't want to show up late. Misora turned to her father and happily said, "Wow Dad, I'm happy that you decided to use one of your vacation days to go on the field trip with us!" Soichi smiled at Misora and replied "It sounded like too much fun for me not to go! Plus, I get to spend the day with my favorite people in the world, sounds like a vacation to me!" Misora hugged her father and said, "I think so too!"

The trio then heard a gruff voice call out, "Well, look who's here bright and early." They turned their heads to be met with the sight of Shota Aizawa aka Eraserhead. Sento approached the teacher and greeted, "Good morning, Aizawa-sensei! How's everything going?" Eraserhead smirked at the question "Preparations are complete for the trip, if that's what you mean." Eraserhead turned his attention to Soichi and asked, "Who's the gentlemen you've both brought with you?" Owner walked up to the pro hero and introduced himself, "Yo! I'm Soichi Isurugi. I'm Misora-chan's father. I'm coming along on this trip to keep Sento and my daughter company. I hope that isn't any inconvenience?"

Eraserhead bluntly responded, "No inconvenience at all." Soichi then held out his right hand, offering a handshake. Aizawa looked the man wearily for a moment, before mimicking Soichi's gesture and shaking the man's hand. Just then, Ryuga Banjo and Kasumi Ogura had arrived, carrying their backpacks and a few snacks and other necessities. Misora quickly ran up to her best friend, gave her a big hug, and squealed, "Kasumi-chan! Good morning! I'm so glad to see you and Banjo!" Kasumi returned Misora's affectionate hug and said, "You too, Misora-chan! We're really excited for the trip, aren't we Ryuga?"

Banjo nodded in agreement with his girlfriend, "Yup! Today's going to be awesome!" Sento approached his muscle-bound friend and told him, "I agree, Banjo. This will be an excellent opportunity to educate our underclassmen, as well as show them around the Institute!" Banjo then took notice of Soichi and greeted him, "Hey there, Owner! What are you doing here?" Soichi smirked at the young man, telling him, "Well Banjo, I had some vacation days saved up from my other job, so I decided to use one today to go on this field trip with you all! Hope I'm not intruding?" Banjo grinned and said, "No complaints here!"

A few minutes later, some of class 1-A's students began to show up. Izuku and Momo were the first ones to arrive. Seeing the Build crew talking to one another in front of the school bus, the two first-years approached their seniors. Izuku waved at them and said, "Hello, Sento-senpai! Misora, Banjo, and Kasumi-senpai too! I hope that you're all having a good day so far!" Sento was the first to greet the younger boy, "Yes, we are! I hope you're ready to visit the Institute, Izuku!" The green-haired student answered, "Of course! The Touto Institute of Advanced Matter Physics is one of the most renowned research facilities in the whole world! The only other places that come close are I-Island and Seito University Hospital!" As Izuku continued to mutter his thoughts to Sento, who was eagerly listening to his fellow UA student, Momo walked over to Banjo, Kasumi and Misora commenting, "Goodness, Midoriya-san seems to get quite excited when talking about science-related topics! Not that I cannot relate."

Misora nodded at Momo's statement and said, "Don't worry Momo-chan, Sento is the same way! Whenever he gets a new idea in that bright head of his, I have to bring him back to reality or else, he'll just spend the entire day thinking about Physics equations." At the mention of Physics, Momo perked up "Will we be seeing some of Sento-senpai's ideas at the Institute?" Misora mimicked a zipping motion across her mouth and told Momo, "Maybe, but you'll have to wait until we get there. Can't spoil the surprise after all!" Momo pouted a little but understood the older girl's reasoning.

Ochako and Tenya were the next class 1-A students to arrive at the front gate. Ochako saw Izuku talking up a storm with Sento, who was also contributing to the conversation. Both appeared to be quite excited to have someone to exchange ideas with. The brown-haired girl had an idea to get Izuku's attention. She slowly approached the two, with Tenya looking confused at his new friend's actions. She eventually decided to sneak behind Izuku. Sento noticed her approaching, then turned his head to the rest of the Build crew. Misora had her index finger extended over her lips, suggesting that he not interrupt whatever Ochako was about to do. Banjo had his hands behind his head and whistled, pretending not to see anything. Kasumi gave him a thumbs-up and Momo simply closed her eyes and smiled.

Turning back to Izuku, Sento stopped the boy mid-conversation and pointed up, "What's that up there?!" Izuku looked up asking, "Huh? I don't see anything." Suddenly, two hands covered Izuku's eyes and the person responsible asked, "Guess who?" Izuku blushed a bright red after hearing the familiar female voice and answered, "Is that you, Uraraka-san?" Ochako then removed her hands. Izuku turned to face his friend and she smiled, "Yep! It's me, Deku-kun!" Izuku smiled at Ochako and said, "You got me, Uraraka-san!" Ochako gave Izuku a peace sign with her fingers. Tenya had chosen to now walk up to his friends. He greeted Izuku "Midoriya-kun, I hope that you weren't too startled by Uraraka-kun's stealthy surprise."

Izuku replied "No worries, Iida-kun! I'm so excited for this trip, that even Uraraka-san's greeting didn't spook me too much." Satisfied with his friend's response, Iida adjusted his glasses on his face and said "Very good. Having such nerves of steel will definitely be of help to you in the future. I'm sure of it!" Izuku nodded at what Tenya had said. As the rest of class 1-A's students began to arrive, Aizawa was ushering them over to fill up the bus that would take them to the Institute. The Build crew plus Soichi got the frontmost seats behind Eraserhead, who was driving the bus. Behind them were Izuku, who sat next to Ochako, Tenya who sat next to Tokoyami, Todoroki next to Momo, and so on.

It was 8:50 AM and Aizawa turned to Sento "Alright Sento, since this trip was your idea, it seems only fair that you take care of things from here." Sento replied "Of course, Aizawa-sensei!" Sento stood up from his spot next to Misora to the aisle between the bus seats. He cleared his throat and addressed class 1-A "Good Morning, class 1-A! By now, you all know me as Sento Kiryu. Aizawa-sensei has placed me in charge of today's activities. Our field trip today will be taking place at the Touto Institute of Advanced Matter Physics." Sento reached into his bag and pulled out a stack of papers. He then began to pass out a copy of the papers to all of the 1-A students.

Bakugo questioned "Oi! What's this paper that you're handing us?" Sento looked right at Bakugo and said "That Bakugo, is a Non-disclosure agreement form that I'm having you and the rest of class 1-A sign before we reach the Institute." Mina Ashido raised her hand and shouted "Sento-senpai!" Sento asked "Yes, Ms. Ashido?" Mina asked the genius "Why do we have to sign these papers?" Sento closed his eyes, crossed his arms behind his back and answered "I'm having you all sign this as during today's field trip to the Institute, you will see technology, inventions, and information that we do not want to fall into the wrong hands. As students of UA High, we are expected to act in a manner that benefits society."

Izuku chose then to raise his hands to ask his own question "Sento-senpai! Does that mean that you're going to reveal information about the Nebula Gas quirk that you, Misora and Banjo-senpai share?" Sento nodded in confirmation "Yes Izuku, by the end of our trip, you will all know the inner workings of the quirk. That is why we are requiring you to sign the agreement, promising that none of you openly tell anyone about what you see at the Institute with permission." Izuku supplied "Don't worry, I'm sure that no one here would tell a soul." As if to confirm what Izuku had said, all of the students pulled out pens from their backpacks and signed the agreements, returning the signed forms to Sento.

Sento gave a curt bow and thanked the class "Myself and the rest of the Build crew really appreciate this." Misora chimed in "Yes, I know that you are all trustworthy." Banjo spoke up "You guys are going to love the place!" Kasumi added "We hope that you all have a wonderful time!"

* * *

The bus had arrived at the Institute. The students had left the bus and were standing in front of the building. Everyone from class 1-A were astounded at the impressiveness of the Institute. It was a very tall white building with many glass windows. There were many smaller buildings surrounding it, facilities like a garage for cars, a gym for healthy exercise, a warehouse for machinery and much more. Todoroki asked Sento "Does this whole Institute really belong to you?" Sento gave Shoto a solemn smile and told him "Yeah, my parents were the previous heads of the Institute. They left it all to me before they died."

Misora gave Sento a worried look, before Sento quickly shook off the negative feeling and smiled at her. Sento then walked up to the front door of the Institute in front of class 1-A, with Misora, Banjo, Kasumi and Soichi beside him. Eraserhead stood behind the class 1-A students with his arms crossed, more than happy to allow Sento to be responsible for the field trip taking place at the boy's company. Just as Sento was about to begin the tour, Izuku had taken notice of Soichi and asked him "Excuse me, Sento-senpai? Who is that gentlemen standing over there with you guys?" Sento blinked and remembered that he never did introduce Owner to class 1-A. He responded "Ah yes, how silly of me! This man over here is my Godfather, Misora's father, former astronaut and Vice-Director of the Touto Institute of Advanced Matter Physics, Mr. Soichi Isurugi!"

After the stellar introduction, Soichi had stepped forward and tipped his hat up a bit as a greeting. He addressed the first-year students "Yo! Just as Sento explained, my name is Soichi. I decided to tag along on this field trip as I had some vacation days from my second job, and I figured that I'd spend the day with my Misora-chan, Sento-kun, and see how the Institute is doing." Most of class 1-A had seen Soichi as an excitable and fun guy. The only ones who were skeptical were Izuku, Shoto, Bakugo, and Aizawa. Izuku thought to himself _"I'm getting a weird feeling from Mr. Isurugi, I hope that it's nothing bad."_

With the introductions out of the way, Sento began the tour "Welcome to the Touto Institute, class 1-A of UA! We hope that you enjoy the trip and more importantly, you all learn something during the tour!" Izuku looked estatic for the tour. Ochako, Momo, Mina and Tooru jumped up and down in excitement, while Tsuyu and Jiro were more reserved in showing their interest. Kirishima and Kaminari looked pumped, Shoto and Bakugo were eager to see the facility, and the rest of the boys were ready for the trip to start. Sento and the Build crew approached the front door and Sento said "Now, without further ado, let us begin the tour!"

 **(Steins;Gate [VN] OST – Laboratory starts playing)**

As the students entered the Institute, they were met with the sight of the inside of the building. They had entered the Research area via the side entrance. There were numerous scientists wearing white lab coats, jotting down notes on the clipboards they were holding. The employees of the Institute had taken notice of Sento and his guests and turned to face them. Taizo, one of the researchers, had approached the Build crew and class 1-A to greet them. He stretched out his hand to Sento and said "Good Morning Sento! It's been quite a while since we've last seen you!" Taizo turned to Misora, Soichi, Banjo and Kasumi and greeted them too "Ah Misora-chan! Vice-Director Soichi-san! Banjo-kun and Kasumi-chan as well! A good morning to you all too!" Soichi waved at the employee "Yo Taizo-kun, I trust that the Institute has been well cared for in our absence?"

Taizo nodded and explained "Yes, ever since Sento entrusted the Directorship to Takumi-kun, research and development has never been more promising!" Taizo had then noticed UA's class 1-A students and the pro hero Eraserhead were present and he recalled "Oh, that's right! Today is the field trip that Sento informed us about! Well, allow me to offer my services as your tour guid…" Before Taizo could finish his sentence, a male voice spoke up "Don't worry, I'll be the one to lead the tour." Everyone present turned to see who had said that and they were all met with the Co-Director of the Touto Institute of Advanced Matter Physics, Takumi Katsuragi. He was wearing the same type of lab coat as the employees, with the difference that he also had a pair of lab goggles hanging from his neck and blue latex gloves on his hands.

Sento was quick to welcome his friend "Hello Takumi! Are you sure that leading the tour won't take time away from our research?" Takumi smiled openly at Sento and company proclaiming "No actually, we've been making great strides and you just so happened to catch us on a slow day. I'm more than happy to help you show the UA first-years the Institute!" Takumi then walked over to class 1-A and introduced himself "Hello UA freshmen! My name is Takumi Katsuragi, Co-Director of the Touto Institute of Advanced Matter Physics alongside Sento Kiryu. I will be showing you all around the facility, so if any of you have any questions, feel free to ask them! Also, Taizo, you may return to your electromagnetic pulse experiments." Taizo saluted Takumi and Sento and answered "Yes sir! Much appreciated!"

Tooru Hagaku was the first to raise her arm up to ask a question. Takumi took notice of the invisible girl, he pointed to her and asked "Yes, you have a question miss…?" Tooru waved her arms in an excited fashion and said "Hi! I'm Tooru Hagakure! My question is how come you're running the Institute if Sento-senpai is the Director?" Takumi elaborated "Sento named me Co-Director shortly before he, Banjo and Misora took their entrance exam. He appointed me Acting Director due to his enrollment at UA and his budding hero career as leader of the Build crew. Does that answer your question, miss Hagakure?" The invisible girl seemed to have nodded and answered "Yes, thank you!"

Takumi turned to address the rest of class 1-A and asked, "Does anyone else have a question that they would like to ask?" Izuku was next to raise his hand with a question. Takumi noticed the young man and said "Ah, you must be Izuku Midoriya. Sento's description of you was spot-on. Now, what is your question, Izuku?" The green-haired hero hopeful posed a serious question "Are we going to find out how Sento, Misora, and Banjo-senpai's Nebula Gas quirk works?" Takumi thinned his lip at what Izuku had asked him. Takumi looked to Sento, with the latter nodding his head as though to affirm what Izuku had asked. Takumi told the class "Yes, at the end of today's tour of the Institute, you will all be made privy to the secret behind the Nebula Gas quirk. However, I would remind you all that having signed the non-disclosure agreements means that none of you are to openly share the knowledge you will receive, correct?"

All of class 1-A nodded in confirmation. Takumi clapped his hands together and said "Good! Now Sento, I'll be leading the tour, but you are ultimately in charge of the field trip." Sento exclaimed "Of course, Takumi! Lead the way!" Takumi instructed the group to follow him further into the Institute. He first led them to the Institute's front desk. Mina Ashido was put off by this and asked Takumi "Oi! What are we doing at some boring old welcome center?" Kasumi was the one to answer Mina's question "Actually, I run the welcome center and the front desk as the Institute's secretary!" Mina looked gob smacked and said "Seriously?! Kasumi-senpai, you're just a year older than us! How do you fit in a job along with going to UA?"

Banjo took the liberty of clearing up Kasumi's workload "Kasumi's REALLY smart, like almost as smart as Sento, Takumi and even principal Nezu! She set up this cool program that lets her manage all the Institute's records from her phone! She doesn't even have to be in the building, so she can attend UA and help us set up our hero agency!" Everyone except for Eraserhead, Sento, Banjo, Misora, Kasumi, Takumi and Soichi were shocked by Banjo's statement. Kyoka proceeded to follow Mina's question with one of her own "What exactly is Kasumi responsible for here at the Institute?"

Takumi looked over to Sento and asked, "Would you care to answer her, Sento?" Sento straightened himself up, making Misora giggle "Can do! You see miss Jiro, Kasumi's place in Touto Institute of Advanced Matter Physics is a crucial one." Sento glanced in the direction of the research center they had just come from "With the time it used to take for myself and now Takumi to organize and lead the facility and all the research projects, the paperwork used to be quite the issue. One of the research groups would finish their assigned experiment, only to be left with the aftermath of having to write up a report and then file it away. After I hired Kasumi as our secretary, her excellent organizational skills made filing the lab reports, finance reports, and company records a breeze!"

A light blush formed on Kasumi's face after hearing the guys praise her abilities "Geez fellas, you sure know how to flatter a girl." Takumi added "Sento and Banjo are correct Kasumi, your presence at Touto Institute has been nothing but a boon to us. Time that would have been spent filing away reports can now be put toward advancing our research into the fields of science and generating profit to sustain the company. I am most happy that Sento hired both you and Banjo." Banjo then spoke up and said "Takumi, show them the testing center!" Takumi knew the reason why Banjo wanted them all to go there, and he coolly said, "Of course Banjo, that is where we are headed next."

The whole of class 1-A tilted their heads in confusion at the grin that Banjo was sporting after bringing up their next destination. Out of curiosity, Shoji asked "Excuse me, could I please inquire what this "testing center" is exactly?" Misora asked Sento "Oh! Could I answer this one?" Sento smiled at his eager girlfriend and nodded. Misora turned to Shoji and the rest of the class and explained "See, the testing center is where the finished experiments go for their final test. Banjo is our tester, as his physical strength makes him the best person to push our inventions to the limit."

Takumi then motioned with his hand for everyone to follow and said "Misora is correct by all counts, now everyone please follow me."

 **(Music stops playing)**

* * *

Takumi and Sento led the curious class 1-A to the testing center. The room was filled with several punching bags being hung from the ceiling, mangled and dented experiments like robots and suits in the corner of the room, and a large metal lab table on which to conduct experiments.

 **(Haikyuu! OST - Haikyuu! starts playing)**

Takumi then gestured his hand over towards Banjo and asked, "Well seeing as the testing center is mainly your facility, would you care to show the students what we do in here, Banjo?" Banjo grinned widely, walked over to the middle of the room in front of the group and said "Sure!"

Banjo punched his right hand balled up in a fist into his left hand. He excitedly exclaimed "Welcome to the testing center guys! This is where Sento and Takumi have me help them test the durability and physical limits of every experiment that comes out of the Institute." Banjo walks up to one of the punching bags and punches it so hard, the bag exploded. The entirety of class 1-A is amazed, with Kirishima yelling "Holy crap, Banjo-senpai! I knew that you were strong, but you just blew up that bag like it was nothing!" Sento explained to everyone present "Banjo was already a very strong individual before he got a quirk. Now that he has one, it makes sense that his already naturally-high strength would increase further. That makes Banjo the perfect person to ensure that our creations can withstand damage from those weaker than Banjo himself."

Takumi was adding notes to the paper he had affixed to his clipboard and began muttering "So, Banjo's immense physical strength can still obliterate our high-grade punching bags. Maybe if we were to use a more durable material? The ones we employ are made of a unique carbon-fiber. If the next bags were to be composed of a 50/50 ratio of leather and silicone, and filled with ground iron as opposed to sand…" Most of class 1-A were surprised to see Takumi muttering and behaving very much like a certain green-haired boy they all know. Ochako saw this and bluntly commented "Wow! Takumi sure is acting a lot like Deku-kun, huh?"

Takumi then set aside his thoughts about strengthening the punching bags and asked Banjo "Banjo, could you do a demonstration test for the class? I have a new suit that I would like to test." Banjo did some arm stretches and said "Of course! Let's see what you got today!" Takumi wheeled out a dummy that was fitted with what appeared to be a silver-colored protective suit (Think of the Avengers suit from Endgame, except with the Build logo where the Avengers logo would have been). Tenya asked Takumi "Is that some sort of protective equipment?" Takumi grinned at Tenya's question and answered "Yes, good eye Tenya! We are testing the functionality of a prototype hero suit that can stand up to most physical forces, gunfire, and even fire as it is partially composed of Tungsten."

Takumi directed "Now everyone, please step back and let Banjo show you the effectiveness of our latest model suit." The class, Eraserhead, and the Build crew plus Soichi all took a few steps back so that they were all near the room's front door. Takumi looked to Kasumi and told her, "Well, Ms. Ogura, please give your boyfriend the good ahead." Kasumi nodded and did just that "Ryuga! You're clear to test!"

Banjo smiled and replied, "Thanks Kasumi!" The muscle-head turned to the training dummy and threw a fiercely strong punch that sent it flying across the room. Takumi was quick to inspect the suit after the blunt force test. Surprised, Takumi shared with everyone present "Oh my! This is the first suit design that Banjo hasn't been able to dent! This test was a huge success!" Takumi turned to Banjo with his hand raised out for a fist bump "We couldn't have done this without your cooperation, thank you Banjo!" Banjo eagerly bumped fists with Takumi and said, "Happy to help dude!"

Soichi told everyone present "You see everyone, that suit was a collaboration between Sento, Takumi, Misora, Kasumi, Banjo and even yours truly. We all contributed to its development in some shape or form. Sento, Takumi and Kasumi agreed upon the materials that would compose the suit, Misora and I helped with the suit's design, and Banjo here would break all of the previous models in order for us to rebuild it with the intent to better it the next time. In fact, the original design of the suit was thought up by Sento's parents, Shinobu and Kyoka Kiryu."

 **(Music stops playing)**

Jiro turned to Sento and calmly asked "Your mom's name was Kyoka like me?" Sento smiled wanly and told her "Yeah, funny that you and she share the same name." Misora had noticed that Sento's mood was going down at the mention of his deceased mother and she took his hand into her own. Surprised, Sento gazed at his beloved girlfriend. Misora lovingly said "It's okay, Sento. I'm sure that Uncle Shinobu and Aunt Kyoka are very proud of you!" Sento tightened his grip on Misora's hand and happily replied "You're right! I needed to hear that, thanks Misora." Misora leaned in close to Sento and pecked him on the cheek, causing all the class 1-A female students to squeal out of sheer cuteness. Misora gently told her boyfriend "I've always got your back."

Ochako had been blushing for a good while since Misora had kissed Sento. As she was standing next to Izuku, she mindlessly blurted "Uh, I guess that when you love someone like that, there isn't anything you wouldn't do for them. Isn't that right, Deku-kun?" Izuku stiffened at the unexpected question that was thrown his way, rubbed the back of his head and said "Well, I'm not familiar with THAT kind of love. After all, I've never had a girlfriend." Ochako replied "Is that right?" Internally however, Ochako was elated _"Oh man! Deku-kun is single! Relax girl, remember why you're attending UA! For now, we can be good friends. Maybe more if things improve."_

Takumi announced, "Okay everyone, Sento will now lead us for the reminder of the tour as he can best explain the areas that are left to see." Sento stepped forward and with a huge smile on his face, exclaimed "Alright, let's continue with the tour, shall we?"

* * *

 **(Kamen Rider Build Soundtrack CD1 04 Sento's room starts playing)**

Sento led the group around the rest of the Institute. He showed them all the indoor gym that the staff use for exercise and to destress. Banjo had enthusiastically shown Izuku, Todoroki, Bakugo, Kirishima and the rest of the male students who were interested, all the gym equipment. He and Kirishima had challenged each other to contest of who could lift the most weight. Both boys, as well as everybody minus Bakugo, were surprised when Izuku had joined them in their lifting and was keeping pace with the muscleheads. Ochako was not so subtly drooling over Izuku's ripped biceps as he was doing bicep curls.

Misora, Kasumi, Mina, Asui, and Tooru all winked at Ochako and gave her a thumbs-up, causing the poor gravity girl's face to erupt in a bright red blush and wave her arms in front of her face crying out "It's not what it looks like!"

The next area of the Institute that Sento had led the group to was the Cafeteria/Kitchen. Eraserhead and the class 1-A students were beyond impressed with how fancy and clean the place was. Even Momo, who is accustomed to a higher standard of living remarked "Goodness, this kitchen is even nicer than the ones we have back at the mansion!" Misora smiled widely and told the group "That's because Sento personally handled the reconstruction of this area! He drew up an initial design for the builders, and even helped to make this kitchen!" There was a stainless-steel buffet counter with various foods, deserts, and drinks. In the back of the room, was the cooking area, complete with several ovens, stove-tops, a brick pizza oven, deep fryers, food processors, and every type of kitchen equipment imaginable.

Sento gave the group a short bow, much like a butler would. He presented the facility "Here, is the Cafeteria/Kitchen area of Touto Institute! As the company makes quite a bit of money from our various projects, we are able to fully stock the kitchen to suit the needs and tastes of our beloved staff members. I helped to remodel this room to include a cafeteria, for occasions such as today where we are receiving guests!" Sento had taken notice of the starry-eyed freshmen and the hungry looks on their faces. The genius chuckled slightly and told them "After we've finished the tour, we will be returning here for lunch. It's all free, of course! Only the best for UA's newest future heroes, after all!"

Class 1-A yelled out "All right!" Aizawa blinked and asked the young director "Yo Sento, are you sure about that? From what I can see, some of these kids can put away quite a bit of food." The scruffy underground hero put both his hands into his pants pockets and managed to get out "You sure that it won't be a problem?" Banjo spoke up "It's all good, Aizawa-sensei! Sento and Takumi put enough of the budget towards the cafeteria to feed a small army! You should have seen some of the lunches that Kasumi and I eat when we're here at work!" Kasumi stepped forward so that she was standing next to Banjo, in front of Eraserhead "Ryuga is absolutely right! The Institute's kitchen can easily handle feeding us all and then some! The first time that we ate here, Sento treated us to a nice lunch that I could have sworn came out of a five-star restaurant!"

Sento raised his right fist to his chest and told his teacher "Don't worry Aizawa-sensei, our kitchen is perfectly capable of meeting everyone's nutritional needs!" Momo then shyly asked the Build crew "Um, do you think that you could meet my dietary requirements then? Due to my quirk Creation, I can create objects by using the fat in my body as fuel. This means that I must consume much more food than the average person." Misora clasped Momo's hands and told her "Don't you worry! Sento can make anything, whether it's an invention or food! We'll make you that you're well fed, Momo-chan!" Momo shot Misora a look of relief and gratitude and said, "I'm very grateful, Misora-senpai." Misora shook her head and correctly the black-haired rich girl "We're friends now, so call me Misora-chan!" Momo began to stammer "Oh gracious, I simply couldn't! You belong to class 2-A, which makes you my senior. I must show you the proper respect!" Misora good-naturedly stuck out her tongue and told Momo "You can respect me just fine as my friend!" Momo composed herself and said "Okay then, Misora-chan."

Misora hugged the creation girl and called out to Kasumi and the other class 1-A girls to discuss all manner of things like food, fashion, favorite heroes, etc.

Sento then led the group to the planetarium that was housed in the center of the Institute's main building. Izuku was soaking in the vibe of outer space that the room was giving off. The room consisted of models of the planets in Earth's solar system. There was the Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. The Earth's Moon was also featured among the models, next to the Earth. Izuku, Ochako, Momo, Aoyama, and the rest of class 1-A were amazed by the exhibit. Takumi, who was standing by the light switch near the entrance, turned off the lights. A projector that was mounted on the ceiling lit up and put a starry night sky all over the room. It made everyone present feel as though they were all really in outer space. Soichi in particular, was looking at the model of planet Mars with a strange glint in his eyes, that went unnoticed to everyone present.

Finally, Sento brought the group to the last leg of the field trip at the Institute. The room that everyone had entered was mostly white in color. What stood out the most in the room was the large machine in the back that had what looked like a microwave attached to it. To the right of the contraption, was a workbench with blueprints of inventions and random ideas and equations on paper scattered across it. The Drill Crusher was also on the workbench as well as an orange and black colored gatling gun. There was also a black chamber with a square glass window on it over by the large machine. The main attraction however, was the unique black box that was on a stand opposite the workbench, being shielded by a glass case.

Sento spread his arms out in front the room and proudly exclaimed "Here we are! The last area on the tour, my personal laboratory!" Izuku had noticed the box that was in the glass case and asked "Sento-senpai! Is that the Pandora Box?"

 **(Music stops playing)**

* * *

 **(Kamen Rider Build Soundtrack CD1 37 The Pandora Box starts playing)**

Takumi was the one who answered Izuku instead "Indeed Izuku, beneath that glass case is one of the single most important objects in the world, the Pandora Box." Mina raised her hand to ask, "Wait a sec, what's so special about that box?" Sento decided that it was time to drop the bomb "Well for starters, the Pandora Box is the source of the quirk Banjo, Misora and myself all share, Nebula Gas!" The class 1-A freshmen collectively lost it at that point and they all shouted out "WHAT!?" Brushing off the confusion in the room, Sento continued "Maybe I should explain things a bit better."

Sento walked over to the stand where the Pandora Box was placed and put his hand on top of the glass case. Sento began "Everything started when my parents, who were the Institute's first Directors, created the Touto Institute of Advanced Matter Physics." The young genius turned his gaze to the portrait of his parents that was mounted on the wall behind the Pandora Box. It showed Shinobu and Kyoka Kiryu standing happily in front of the Institute with Kyoka carefully holding a 1-year old baby Sento in her arms.

Sento explained "My parents founded the Institute with the help of many of the scientists you all saw working in the Research area, as well as our board advisors who many of which were very close to my mother and father." He gestured over to Soichi and told everyone "But the person on the board who was the closest to them was Mr. Soichi Isurugi, who is Misora's dad, my godfather, and a dearly valued family friend who has helped us for many years!" Soichi took his fedora off his head and placed it over his chest and said, "Don't forget that I'm also the Vice-Director under you and Takumi-kun!"

Sento grinned and playfully said "Of course not, Owner!" Rikido Sato raised his hand, with a question ready "Excuse me, Sento-senpai? Why do you guys call Mr. Isurugi Owner?" Sento readily responded "Well Sato, we refer to him as Owner because he is the owner of the café Nascita, where he, Misora and I work. It's also our home. All of our customers also call him Owner as well, likely due to the great service we provide them." Sero then hurriedly asked "Wow, you own the Institute, work at a café, and attend UA? How do you find the time to handle all of that?"

Sento casually addressed the question "Well, I appointed Takumi as Acting Director of the Institute to free up time, so I could attend UA. As for the café, Misora and I run it now as Owner's second job keeps him quite busy. He helps when he is there though. Ironically enough, due to the Build crew's growing popularity as a hero team, the café is now often filled with fans who want to meet us and end up as customers after looking at what we serve."

Sento briefly glanced over towards Banjo and Kasumi and remarked "Banjo and Kasumi help out at the café every now and then, and we reward them with suitable pay and free food!" Misora then clapped her hands together and said, "You're all welcome to visit the café whenever you'd like!"

Sento resumed his explanation about the Pandora Box "Back to business! See, Owner was an astronaut 10 years ago, and my parents and the Institute had him embark on a trip to Mars." Eraserhead turned to Soichi and commented "Huh looking at you now, I wouldn't have ever guessed that you were a former astronaut, Mr. Isurugi." Soichi merely smiled in a placid manner and said, "I've done a lot with my life, not everything is worth mentioning." Eraserhead simply looked back to Sento, as he continued his explanation.

Sento stated "Owner discovered the Pandora Box among some ancient Martian ruins, presumably from a dead civilization. He brought it and other objects that he found there back to Earth." Sento then pointed to Misora's wrist and said, "That gold bracelet around Misora's wrist was one of the items he brought back, he gifted it to her as a souvenir from the trip." Sento grimaced a bit and carefully explained "After the Pandora Box was brought to Earth, Owner gave the Box to my parents as he felt that they were the best people to unlock its secrets. This didn't sit well with the Hokuto and Seito prime ministers as they had helped to fund the shuttle launch."

The genius raised his right index finger to his temple and continued "During this, my parents had discovered 60 unique bottles that were affixed to the panels of the box, 10 bottles per panel. These were the fullbottles that you all witnessed Banjo, Misora and I use the other day during the quirk assessment test. Touto's prime minister Taizan Himuro decided to give 20 fullbottles to Hokuto, 20 to Seito, and keep 20 of them for ourselves as an act of fairness. It was also a sort of challenge to see which region could collect all 60 and solve the Pandora Box's mystery."

"However, during the distribution of the bottles, some rogue villain attempted to steal all 60 fullbottles before they could be given to the prime ministers. The thief had been too hasty in trying to steal the bottles and had ended up knocked a few of them over. The essences within some of the bottles were scattered across Japan. Afterwards, the bottles were still given away as well as the empty ones, as the essences could still be recovered."

Sento proudly said "In fact, two of those essences, the Rabbit and Tank, found their way inside of me as my parents later discovered. Banjo also had the essence of the Dragon find him as well. Those were placed back inside of their empty bottles and were restored. The Pandora Box produces a substance we call Nebula Gas. Incidentally, that is also the name of our quirk. My parents discovered that enough exposure to the Nebula Gas would grant a person the quirk." Sento walked over to the whiteboard and grabbed a black marker. He drew the Pandora Box, then an arrow pointing to a gaseous cloud, then an arrow pointing to a gas chamber, an arrow which pointed to the Rabbit and Tank fullbottles, and finally, an arrow pointing to the Build Driver and Kamen Rider Build standing next to it.

Sento elaborated on his drawings "This process is quite simple. First, one must have either the whole Pandora Box or at least one of the Panels in their possession in order to produce Nebula Gas. Second, the subject then enters a special gas chamber that will introduce the Nebula Gas into their system. This step usually requires a full 24 hours for the gas to be fully absorbed into the host. Afterwards, the formerly quirkless individual should find themselves now in possession of the Nebula Gas quirk! This is a huge accomplishment as my parents discovered proof that quirks exist outside of planet Earth!"

Misora placed her closed hand over her mouth and coughed, signaling Sento to get back on track. The young intellect resumed "Back to the process, simply having Nebula Gas isn't enough on its own. The quirk's true power showcases itself when one utilizes the Rider System" Sento drew the Build logo in the center of his diagram on the whiteboard. He shared with the group "Before they passed away, my parents devised what would become the beginning of the Build Rider System. A method which would allow a Nebula Gas quirk user to reach their full potential. You see, Nebula Gas is a transformation-type quirk and to transform with it, one needs a Build Driver." Sento held out his own Build Driver and showed it to the group.

Todoroki then raised his hand and asked, "Your folks built the Driver, correct?" Sento grinned at the boy's question and answered "Correct!" He placed the Driver on his waist, causing the belt straps hold the Driver in place. He then grabbed the Rabbit and Tank fullbottles from his coat pocket and shook them up and down. He explained "Normally, one transforms into a Kamen Rider by matching an organic fullbottle like Rabbit with its inorganic match, in this case the Tank fullbottle. This results in a Best Match, where the bottles synergize with each other and produce a stronger form than if the bottles didn't match. Once that's done,"

Sento placed the bottles in the Driver:

 **RABBIT!**

 **TANK!**

 **BEST MATCH!**

Sento turned the Vortex Lever on the Driver, making the two halfbodies, one red and the other blue appear. The Driver then asked:

 **ARE YOU READY?**

Sento posed and said "Henshin!" The halfbodies snapped together, encasing Sento in armor. The Driver announced:

 **FULLMETAL MOONSAULT!**

 **RABBIT! TANK!**

 **YEAH!**

In front of the students and company, was Kamen Rider Build. Sento finished with "To use the Build Driver, one must have a high enough Hazard Level. This is a measure of how much resistance to the Nebula Gas a person has. The Build Driver requires that a Nebula Gas user has a Hazard Level of at least 3.0." Sento concluded his explanation of the Pandora Box and the Rider System by disengaging his transformation and asked the class 1-A students "Any questions?"

Each one of them shot a hand up into the air, eager to ask some questions of the young physicist. Seeing how rowdy everyone was being and have noted the looks of amusement on Banjo, Kasumi, Soichi and Misora's faces, Sento opted to implement a simple solution. He shouted "Everyone can ask me one question each, and then we'll end the trip with that lunch I promised you all! Does that sound fair?" The students all nodded in agreement. Sento sighed "Good. Let's start with the girls. Now first up, let's hear from Ochako." The gravity girl shyly asked "Is the Institute currently hiring? My quirk is Zero Gravity, I can make people and objects virtually weightless. The only drawback is that if I push it too much, I get nauseous. I was hoping to maybe apply to be a tester like Banjo-senpai! I really need to make some extra cash, and this seems like a great place!"

A lock of Sento's hair popped out due to his eagerness after hearing Ochako's plea. It settled back into place and Sento told Takumi "Takumi, you hire this girl immediately! I like her attitude!" Takumi chuckled and told his Co-Director "Of course Sento, I figured that something like this would happen." Takumi walked up to Ochako, handed her some forms and told her "We can hire you as a part-time tester for the Institute. Just go over your schedule so that this doesn't interfere with your studies and everything should be fine." Ochako excitedly asked "Wait, just like that?!" Misora answered the brunette "Yup! Just like that!" The rest of the girls and most of the boys of class 1-A had asked Sento their questions. They varied from how loaded Sento was, his favorite color, and questions about his and Misora's relationship from the girls (mostly Mina).

The last one to ask Sento a question was Izuku. The green-haired kid confidently asked the genius "How are you determining who gets the Nebula Gas quirk?" Sento was visibly proud of Izuku for asking that important question. Sento told him "You know, prime minister Himuro asked me that very same question after he first saw me use this quirk. Right now, Banjo, Misora and I are the only known Nebula Gas users. I'm trying to keep the number of Kamen Riders to a minimum for now as I don't want to accidently grant the quirk to someone who might become a villain. Or worse, one of the other regions or another country might get some funny ideas and attempt to create their own Nebula Gas empowered soldiers to use for war. I won't abide by that!"

Izuku gave a sigh of relief that his senior was being responsible about who he allowed to receive the quirk.

Banjo's stomach started growling out of nowhere, causing everyone present to look in his direction. The musclehead rubbed the back of his head and asked "If we're done here, can we please go grab some lunch? I'm starving!"

Sento agreed and said "Sure thing Banjo. This concludes the tour of the Institute. Now, let's all head back down to the cafeteria!"

 **(Music stops playing)**

* * *

After everyone had eaten their fill and were reasonably satisfied, Sento and the rest of the Build crew were about to lead the rest of the group back to the bus to go home. Out of nowhere, the Institute's alarms started to sound off quite loudly, akin to police sirens. Eraserhead used his pro hero tone of voice and asked Sento "What's going on, Sento?!" As if to answer Aizawa's question, the Institute's speaker system projected Taizo's voice to every building in the Institute "Directors Sento and Takumi! Our security cameras are receiving live footage that a couple of Smash are headed toward the Institute! What should we do?!"

Sento ran up to one of the Institute's comm phones that put him through to Taizo and he directed "Taizo, get yourself and the other scientists to the panic room near the research area! We'll deal with the Smash!" Sento looked over to the group, most of the student looking concerned. Sento requested of Takumi "Takumi, please take Kasumi and the others to the security room. Banjo, Misora, you guys come with me. We'll handle this mess!" Takumi nodded and wished the Build crew luck, as the three young heroes headed out to face the monsters.

Takumi, Kasumi, Soichi and class 1-A had all headed over to the security room per Sento's instructions. The room looked very much like a security room from a mall. There were several TV monitors showed live footage from the many cameras placed around the entire Institute. Takumi walked up to the panel, typed on the keyboard, and the center main monitor now displayed what was happened in front of the Institute. The students were scared out of their minds, fearing these unknown monsters nearing them. Three Smash were making their way towards the main building. The one in the middle was slightly bigger than the other two, it also was covered in sharp needles and was mainly white in color.

The cameras showed that Sento, Banjo and Misora had already transformed into Build, Cross-Z and Rescue before engaging the Smash. Taking point as leader, Sento told his crew "I'll take the spiky one, you two take the normal Smash!" Banjo and Misora told him "Got it!" Cross-Z and Rescue took on the two normal Smash, leaving Sento to fight the Needle Smash. The armored physicist noticed something unique about the Smash "This one is carrying an essence!"

Back over to the security room while the others were all witnessing the fight, the students all began to pressure Eraserhead into letting them help the Kamen Riders. Aizawa activated his Erasure quirk, which made his eyes glow an eerie red color and stared intently at class 1-A. Their teacher stated "The Build crew will be all right, remember that I was their homeroom teacher last year. I know exactly what those three are capable of, not to mention that they've had their provisional hero licenses for months now." The gruff hero then turned his attention back to the monitor.

Tenya asked Takumi "Takumi-kun! What are those creatures out there?" The Acting Director told them all "Those are Smash, they are monsters that come about when a person with the Nebula Gas quirk doesn't have enough tolerance and succumbs to the quirk. This results in aggressively rapid cell division almost like cancer, and the subject becomes a Smash. That larger spiky Smash however, seems to have one of the fullbottle essences inside of it. The Build crew will be able to reclaim the essence using an empty Smash bottle."

Izuku then asked the obvious question "Hold on a minute! Those Smash didn't come from the Institute, so how did someone acquire the means to give people the Nebula Gas quirk?" Takumi closed his hand in a tight grip and said "It must have been when the Pandora Box was at the Ministry of Defense. As part of a deal with our prime minister, Sento agreed to have the Box be kept at the ministry every now and then for study. One of the government employees must have figured how to infuse people with the quirk, but without a Build Driver, the subjects went berserk and became Smash." Todoroki asked the Director "How do you turn Smash back into human beings?" Takumi grinned and answered, "If they're defeated by a Kamen Rider, the battle should exhaust their excess Nebula Gas and they'll turn back to normal."

Kasumi took over the briefing "These aren't the first Smash the Build crew have had to deal with. The first time that they appear was ironically enough, when Sento debuted as Build." Kasumi held out her Build Phone and showed everyone footage of the Smash after they were stopped by the Kamen Riders and turned back into humans. She added "The Build crew's main objective currently is to find out who has been turning these innocent people into Smash and setting them loose across the city." After hearing that thoroughly explained exposition, Bakugo pointed at the main monitor and shouted, "If they're really second-years and have their provisional licenses, then this should be a cake walk for them!" Everybody in the room smiled at Bakugo's roundabout compliment.

 **(Kamen Rider Build Soundtrack CD1 8 Build Sortie starts playing)**

Cross-Z was hammering away at the Smash he was fighting. He swung widely at its face, hoping to push it back. It worked, as the Smash fell on its back. Seizing this opportunity, Banjo turned the Vortex Lever on his Build Driver and exclaimed "No one can stop me now!" The Driver announced:

 **READY, GO!**

 **DRAGONIC FINISH!**

Cross-Z had leapt into the air and executed a rider kick. A dragon composed of a bluish energy formed around him as he crashed into the Smash. Sparks flew out of the Smash's body and it fell down. Black Nebula Gas began to seep out of the victim and the Smash turned back into an unconscious man who was wearing a white shirt and pants.

Over with Rescue, Misora had brought out her Reflex Bow and was rapidly firing energy arrows at the Smash from a distance. She then pressed a button on the Bow, and it activated shield mode. She threw the shield at the monster, it struck the creature's face and bounced back towards Rescue, who swiftly caught it. She put away her weapon and cranked the Vortex Lever on her Build Driver and declared "The innocent will be saved!" The Driver announced:

 **READY, GO!**

 **VORTEX FINISH!**

 **YEAH!**

Misora flew into the sky using her white dove wings that emerged from her back, and dropkicked the Smash, trailing down a white energy chart that trapped and led to the monster. Rescue's foot met with the Smash and she landed behind it. The Smash erupted in a shower of sparks and after expelling a lot of Nebula Gas, turned into a passed-out woman wearing all white clothing just like the Smash Banjo defeated.

Banjo ran up to Misora and told her "Yo Misora, I took care of the Smash! You deal with yours?" Misora shot him the peace sign and replied "Of course, was there any doubt?" Banjo laughed and said "Hey, you never know!" Misora looked at Banjo as intensely as she could while in her DovePlane form and said "Well, I know about the time that Kasumi-chan had you model a dress for her once because she gave you the puppy dog eyes." Cross-Z put his hands over his vizors and yelled out "AH! I can't believe that Kasumi told you that, it was supposed to be secret!" Rescue smartly remarked "Banjo, there's never secrets between girls." Cross-Z sighed and said, "Okay smarty-pants, let's go check on your genius boyfriend." Banjo raised his right hand signaling for a high-five, which Misora gladly met.

* * *

Meanwhile over with Build, Sento was running into some issues. This essence-enhanced Smash was proving to be more of an issue than the normal ones. Build had broken out the Drill Crusher and was cutting into the Smash, to little effect. The various needles surrounding the Smash kept the Drill Crusher from making full contact. Sento then yelled "How about this!" He changed the Drill Crusher to gun mode and started to blast at the Needle Smash, hurting it quite a lot. Build remarked "So blasting it is the way to go!" He looked at his weapon and thought _"The Drill Crusher in gun mode isn't quite enough to take down this Smash. In that case…"_

 **(Music stops playing)**

 **(Gundam Build Fighters Try OP 2 – Just Fly Away by EDGE of LIFE starts playing)**

Sento put away the Drill Crusher and reached for his fullbottle holder that was on the left of his Driver. He took out the Orange Hawk and Silver Gatling fullbottles. Sento proudly stated "I've got the winning formula!" Build removed the Rabbit and Tank fullbottles from the Driver and shook the Hawk and Gatling bottles up and down. He placed the bottles in the Build Driver, which announced:

 **HAWK!**

 **GATLING!**

 **BEST MATCH!**

Sento began cranking the Vortex Lever and two halfbodies, one orange and one silver appear. The Driver asked:

 **ARE YOU READY?**

Sento called out "Build Up!" The halfbodies snapped together over Sento's RabbitTank form, changing his suit. The Driver announced:

 **THE SKY VANDAL!**

 **HAWKGATLING!**

 **YEAH!**

Standing fiercely in front of the Needle Smash was Kamen Rider Build HawkGatling form. Build was now half orange and half silver in color. His right vizor was a gatling gun and his left was a hawk. He also had now gained orange wings hanging off of his back. Sento then held out his hand and the Hawk Gatlinger materialized from his lab workbench. Sento then shouted, "With this, you're finished!" Using his newly acquired wings, Build flew up into the air and pointed the Hawk Gatlinger at the Needle Smash. He then flew around the Smash, spinning the Revol-magazine on the gun 10 times, the Hawk Gatlinger sounding off how many shot were loaded as it was spun:

 **TEN!**

 **TWENTY!**

 **THIRTY!**

 **FORTY** **!**

 **FIFTY!**

 **SIXTY!**

 **SEVENTY!**

 **EIGHTY!**

 **NINETY!**

 **ONE HUNDRED!**

 **FULL BULLET!**

A white energy sphere graph had formed around the Needle Smash, and 100 shots from the Hawk Gatlinger collided with it. The end of the attack was signaled by the explosion that followed. The Needle Smash was knocked out cold. Sento, who had just landed on the ground, pulled out an empty Smash bottle. It had a black web-like design over the wide, clear bottle. He twisted the cap and pointed it towards the Needle Smash. The white-colored essence flew out of the Smash and into the bottle, leaving behind an unconscious man. Sento put his hands to his sides and said, "Threat averted!" Cross-Z and Rescue made their way over to Build and noticed that he took care of business on his end. The three of them bumped fists to a job well done and they disengaged their transformations.

 **(Music stops playing)**

Misora threw herself into Sento's arms and gave him a deep hug. She then leaned in and kissed her boyfriend's warm lips. Sento gently responded in kind and returned the kiss with as much love as he could muster for his girl. Banjo was off to the side, grinning at the affectionate display his best friends were having in front of him. He commented out loud "I need to hug Kasumi!" Banjo quickly made his way back into the Institute, while Sento and Misora were holding hands, taking their time back. Sento then remembered something important and pulled out his Build Phone. He called Takumi, who answered immediately. Sento requested "Hey Takumi, could you please call the hospital? The 3 injured need medical attention."

Takumi calmly responded "Already did that Sento. Don't worry, I've sent some of our medical staff to see to the victims while we wait for the ambulances." Sento exclaimed "There's the Institute's Director! Super dependable as always!" Takumi simply stated, "Just doing my job, Sento."

After a long and eventful day, the class 1-A students got on the bus headed back to UA. Sento stopped Eraserhead right before the pro hero entered the bus and said "I'm so sorry about the Smash attack, Aizawa-sensei. I'm glad the Institute's security system had noticed them quickly, or else things could have been worse." Aizawa shrugged and told Sento "You had no control over who sent those things. Just promise me that next time you run into some Smash, you bring me along." Sento nodded and said "Deal!"

Izuku waved at Sento from his window seat next to Ochako and Tenya. The One for All successor shouted "Sento-senpai! Thanks a lot for the field trip, it was a lot of fun!" Sento gave Izuku a thumbs up as a response. Eraserhead drove the bus back to UA. The Build crew, Takumi and Soichi were the only ones left. Soichi suddenly yawned and said "Man, I'm tired. I'm going home to Nascita. Misora! Sento! I'll see you both at home, ciao!" Owner walked home towards the café. Banjo and Kasumi had also bid their farewells and promised to talk more during school the next day. Misora told Sento and Takumi that she was going to go raid the Institute's Kitchen for a snack, and then she and Sento would head home to Nascita.

After Misora left, Sento and Takumi were the only two left. Sento seized this opportunity to show Takumi something. He said, "Follow me, Takumi." The two went back to Sento's lab and both geniuses sat in front of Sento's computer. Sento pulled out a USB flash drive from his coat pocket and told Takumi "After today's events, it's become clear that we need to improve the Rider System. Takumi, please keep what I'm about to show you a secret for now. We'll show the others later." Takumi nodded and asked, "What is this secret?" Sento plugged the flash drive into an open port and several files started to pop up on the computer's screen.

The main file was a blueprint of what looked to be an evolved Build Driver. The heading of the file read: PROJECT SCLASH. Takumi's eyes nearly bulged out of their sockets and he hurriedly spoke "Sento, these are plans for a next-generation Build Driver!" Sento smiled widely and replied to his curious friend "Yes Takumi, and you're going to be the one who will help me build this." Takumi paused for a moment, the asked "Sento, who are we going to get to be the first one to test the Sclash Driver?" Sento submitted "Well…"

Misora had gotten her snack and Sento and Takumi had returned from Sento's lab. She noticed that the two were excited and she commented "Aren't you two looking happy!" Sento smiled at his lovely girlfriend and said, "We were just discussing future projects, that's all." She grabbed Sento by the arm and led him out the exit of the building. They both said goodbye to Takumi and headed home. Takumi was still fixated on who Sento recommended to test out the Sclash Driver once it was finished "So, you chose THAT person. You'll hear no objections from me."

* * *

 **Unknown Location**

Darkness. Shadows and filth. Blood Stalk did not enjoy having to navigate through an underground sewer in order to meet with his former partner in crime, All for One. He was a tricky bastard to find for starters. Most people don't even know that he exists. Blood Stalk vividly remembered all of the chaos and uprisings that he and All for One used to cause on a near daily basis way back when quirks were just discovered. Their goals were similar and their personalities even more so. The two were about as close as two siblings. Blood Stalk reached the end of the tunnel and found All for One, sitting in a chair with IV fluid bags attached to him and most of his face destroyed.

 **(CW's The Flash Soundtrack - Eobard Desiccates Wells starts playing)**

All for One began the conversation immediately "My old friend Blood Stalk! Or do you prefer,?" Before All for One could finish, Blood Stalk raised his hands in a surrendering manner and said, "Blood Stalk works." Stalk grinned evilly underneath his helmet and said "It's been too long, my friend! Look what they did to you!" Stalk shook his head and continued "I'm sorry that I wasn't there when you and All Might had your titanic fight." All for One waved off Stalk's apology and said "No need for apologies, I don't fault you for my present condition. In fact, one could say that we're now both in similar boats, don't you agree? We're both stuck somewhere that we don't want to be and we're merely shadows of our former selves."

All for One then weaved his fingers together and rested his chin over his hands. He proposed to Blood Stalk "What if we could get it all back? Not just what we lost, but also revenge! Sweet, sweet revenge!" The Symbol of Evil's words were resonating with Blood Stalk. Stalk laughed joyfully and said, "I knew I made the right decision in coming here tonight!" Blood Stalk pulled out his TranSteam Gun and chillingly said "Once more! Let's turn this world upside down once more!" As both villains began laughing, it was at this moment that an alliance of evil was truly cemented.

* * *

 **A/N: There we go! This concludes the field trip chapter. Next chapter, we'll see class 1-A take on combat training with All Might leading them. How will events differ from the canon? Will we see a kinder Bakugo, will Izuku prove his meddle as a hero? Is Sento getting ever so closer to finding his parent's killer?**

 **Man, I got chills as I was writing the meeting between Blood Stalk and All for One. As evidenced by this chapter, I'm going to be ramping things up for both the heroes and the villains.**

 **So, until next time, Plus Ultra! DarkAbyssBreak is back at it!**


End file.
